Baiquan Wang

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Name: 王佰全; BaiQuan Wang

Organization: Nankai University , China

Department: Department of Chemistry

Title: Professor(PhD)

TOPICS

Organic Chemistry

C-H Activation Amination

Chemicals
References

Synthesis of Diruthenium Complexes Derived from Pyridyl-Substituted Indenes

Co-reporter:Dawei Gong, Bowen Hu, Jing Shi, Peipei Ma, Baiquan Wang, and Dafa Chen

Organometallics March 13, 2017 Volume 36(Issue 5) pp:1066-1066

Publication Date(Web):February 24, 2017

DOI:10.1021/acs.organomet.7b00021

Thermal treatment of the trinuclear ruthenium complex {μ2-η5:η1-(C5H4N)(C9H5)}Ru3(CO)9 (1) with 1,5-heptadiene, diallyl sulfide, 1,4-hexadiene, and 1,7-octadiene respectively generated the series of diruthenium products {(C5H4N)(μ2-η5,η1-C9H5CHCH2CH2R)}Ru2(CO)x (4, R = −CH2CH═CHCH3; 6, R = SCH2CH═CH2; 7, R = −CH═CHCH3; 8, R = −(CH2)3CH═CH2) via the insertion of an terminal C═C bond into the Ru–C(η1) bond of 1. When 1 was treated with diallyl ether, the complex {(C5H4N)(μ2-η5,η3-C9H5CCH2CH2OCCHCH3)}Ru2(CO)4 (5) with a five-membered oxygen-containing heterocycle was produced. Reactions of 2-methyl-3-(2-pyridyl)indene or 2,5-dimethyl-3-(2-pyridyl)indene with Ru3(CO)12 gave the cycloruthenated complexes {(C5H4N)(μ2-η5,η1-RC9H4CH2)}Ru2(CO)5 (9, R = H; 10, R = CH3) with structures similar to those of 4, 7, and 8, via C(sp3)–H activation. The molecular structures of 5–7 and 10 were determined by X-ray diffraction.

Copper-Mediated Annulation of Phosphorus-Containing Arenes with Alkynes: An Approach to Phosphindolium Salts

Co-reporter:Qingmei Ge, Jiarui Zong, Bin Li, and Baiquan Wang

Organic Letters December 15, 2017 Volume 19(Issue 24) pp:6670-6670

Publication Date(Web):December 6, 2017

DOI:10.1021/acs.orglett.7b03394

A novel method for the synthesis of π-conjugated phosphindolium salts via copper-mediated C–H functionalization of trisubstituted phosphines with alkynes in a single step is reported. The reactions are highly regioselective with unsymmetrical aryl-alkyl-substituted alkynes. This protocol provides an unprecedented atom- and step-efficient access to valuable phosphindolium salts.

Rhodium-catalyzed C2 and C4 C–H activation/annulation of 3-(1H-indol-3-yl)-3-oxopropanenitriles with internal alkynes: a facile access to substituted and fused carbazoles

Co-reporter:Tao Zhou;Bin Li

Chemical Communications 2017 vol. 53(Issue 47) pp:6343-6346

Publication Date(Web):2017/06/08

DOI:10.1039/C7CC02808C

Rhodium-catalyzed oxidative annulation reactions of 3-(1H-indol-3-yl)-3-oxopropanenitriles with internal alkynes have been developed. A series of substituted carbazoles and 4H-oxepino[2,3,4,5-def]carbazoles, through a formal Rh(III)-catalyzed (4+2) cycloaddition with an alkyne and tandem (4+2) and (5+2) cycloaddition with two molecules of alkynes, were obtained. The reactions involved sequential cleavage of C(sp2)–H/C(sp3)–H bonds and annulation with an alkyne in the first step, and sequential cleavage of C(sp2)–H/O–H bonds and annulation with another alkyne in the second step. Some of the 4H-oxepino[2,3,4,5-def]carbazole products exhibit intense fluorescence in the solid state.

Comparative investigation of the reactivities between catalysts [Cp*RhCl2]2 and [Cp*IrCl2]2 in the oxidative annulation of isoquinolones with alkynes: a combined experimental and computational study

Co-reporter:Chaoyue Zhao;Qingmei Ge;Xiufang Xu

Organic Chemistry Frontiers 2017 vol. 4(Issue 12) pp:2327-2335

Publication Date(Web):2017/11/21

DOI:10.1039/C7QO00586E

The mechanisms and reactivities of the [Cp*RhCl2]2 and [Cp*IrCl2]2 catalyzed oxidative annulation reaction of isoquinolones with alkynes have been investigated by combined experimental and computational studies. The results have disclosed that the low reactivity of [Cp*IrCl2]2 is attributed to the electron-richness and low electronegativity of Ir(III). These factors make Ir(III) difficult to reduce to Ir(I) and thus lead to a high activation energy of the reductive elimination step. The electronic and steric effects of alkyne substituents on the reactivities have been investigated. Small-sized and strong electron-donating substituents on alkynes should enhance the reactivity of the reaction for both catalysts by not only avoiding the steric repulsion between substrates but also facilitating the reductive elimination. The rate-determining steps for reactions involving [Cp*RhCl2]2 and [Cp*IrCl2]2 are alkyne insertion and reductive elimination, respectively. When an alkyne bearing a small-sized and strong electron-donating substituent NMe2 is employed as a substrate, C–H activation becomes rate determining for both catalysts.

Pd/C-catalyzed synthesis of N-aryl and N-alkyl isoquinolones via CH/NH activation

Co-reporter:Zhen Shu, Yuntao Guo, Wei Li, Baiquan Wang

Catalysis Today 2017 Volume 297(Volume 297) pp:

Publication Date(Web):15 November 2017

DOI:10.1016/j.cattod.2017.02.005

Pd/C-catalyzed direct synthesis of N-aryl and N-alkyl isoquinolones was developed via the annulation reactions of benzamides and alkynes in high yields (up to 99%) through the cleavage of CH/NH bonds. The reaction was ligand-free and air was used as oxidant. High regioselectivities were found when unsymmetrical alkynes or meta-benzamides were used as substrates. The heterocyclic carboxamide substrates, such as furan and thiophene derivatives, also afforded the corresponding products in high yields.Download high-res image (160KB)Download full-size image

Rhodium-Catalyzed Annulation of Tertiary Aniline N-Oxides to N-Alkylindoles: Regioselective C–H Activation, Oxygen-Atom Transfer, and N-Dealkylative Cyclization

Co-reporter:Bin Li, Hong Xu, Huanan Wang, and Baiquan Wang

ACS Catalysis 2016 Volume 6(Issue 6) pp:3856

Publication Date(Web):May 6, 2016

DOI:10.1021/acscatal.6b00311

[Cp*RhIII]-catalyzed annulation of tertiary aniline N-oxides with alkynes was reported to achieve the challenging ortho C–H functionalization of tertiary anilines via N–O bond acting as a traceless directing group. More significantly, this system represents the first example which integrates C–H activation, oxygen-atom transfer, and N-dealkylative cyclization in one reaction. This unprecedented coupling reaction has allowed the construction of N-alkylindole derivatives in high efficiency with broad substrate scope and good functional group tolerance.Keywords: cyclization; C−H activation; C−N bond cleavage; oxygen-atom transfer; tertiary aniline N-oxides

Rh(III)-Catalyzed Carbocyclization of 3-(Indolin-1-yl)-3-oxopropanenitriles with Alkynes and Alkenes through C–H Activation

Co-reporter:Tao Zhou, Yanwei Wang, Bin Li, and Baiquan Wang

Organic Letters 2016 Volume 18(Issue 19) pp:5066-5069

Publication Date(Web):September 20, 2016

DOI:10.1021/acs.orglett.6b02521

Rh(III)-catalyzed carbocyclization reactions of 3-(indolin-1-yl)-3-oxopropanenitriles with alkynes and alkenes have been developed to form 1,7-fused indolines through C–H activation. These reactions have a broad range of substrates and high yields. Unsymmetrical aryl–alkyl substituted alkynes proceeded smoothly with high regioselectivity. Electron-rich alkynes could undergo further oxidative coupling reaction to form polycyclic compounds. For alkenes, 1,2-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-4-ones were formed via C(sp2)–H bond alkenylation and C(sp2)–H, C(sp3)–H oxidative coupling reactions.

Rh(III)-Catalyzed Oxidative Annulation Leading to Substituted Indolizines by Cleavage of C(sp2)–H/C(sp3)–H Bonds

Co-reporter:Bingxue Shen, Bin Li, and Baiquan Wang

Organic Letters 2016 Volume 18(Issue 12) pp:2816-2819

Publication Date(Web):June 7, 2016

DOI:10.1021/acs.orglett.6b01181

Rhodium(III)-catalyzed oxidative annulation reactions of pyridinium trifluoromethanesulfonate salts with alkynes leading to substituted indolizines by cleavage of C(sp2)–H/C(sp3)–H bonds are developed. The starting materials are readily available, and the reactions have a broad substrate scope. This reaction overcomes some drawbacks of the previous indolizine synthetic methods and provides a new efficient route to indolizine derivatives.

Tandem Rh(III)-Catalyzed C–H Amination/Annulation Reactions: Synthesis of Indoloquinoline Derivatives in Water

Co-reporter:Liangliang Shi and Baiquan Wang

Organic Letters 2016 Volume 18(Issue 12) pp:2820-2823

Publication Date(Web):June 7, 2016

DOI:10.1021/acs.orglett.6b01234

An efficient Rh(III)-catalyzed synthetic method for indoloquinoline derivatives from readily available indoles and isoxazoles was developed. This annulation procedure undergoes tandem C–H activation, cyclization, and condensation steps. In this domino cyclization reaction, water is an efficient solvent. A catalytically competent five-membered rhodacycle has been isolated and characterized, thus revealing a key intermediate in the catalytic cycle.

Synthesis of Conjugated Polycyclic Quinoliniums by Rhodium(III)-Catalyzed Multiple C–H Activation and Annulation of Arylpyridiniums with Alkynes

Co-reporter:Qingmei Ge, Yang Hu, Bin Li, and Baiquan Wang

Organic Letters 2016 Volume 18(Issue 10) pp:2483-2486

Publication Date(Web):May 3, 2016

DOI:10.1021/acs.orglett.6b01055

A simple method for the efficient synthesis of highly substituted pyrido[1,2-a]quinolinium- and quinolizino[3,4,5,6-ija]quinolinium-based polyheteroaromatic compounds via rhodium(III)-catalyzed multiple C–H activation annulation reactions has been developed. Moreover, some of the quinolizino[3,4,5,6-ija]quinolinium salts exhibit intense fluorescence and have potential application in optoelectronic materials.

Rhodium(III)-Catalyzed Synthesis of Indole Derivatives From Pyrimidyl-Substituted Anilines and Diazo Compounds

Co-reporter:Ke Yu;Yujie Liang;Bin Li

Advanced Synthesis & Catalysis 2016 Volume 358( Issue 4) pp:661-666

Publication Date(Web):

DOI:10.1002/adsc.201500954

Synthesis of substituted benzo[ij]imidazo[2,1,5-de]quinolizine by rhodium(III)-catalyzed multiple C–H activation and annulations

Co-reporter:Qingmei Ge, Bin Li and Baiquan Wang

Organic & Biomolecular Chemistry 2016 vol. 14(Issue 5) pp:1814-1821

Publication Date(Web):04 Jan 2016

DOI:10.1039/C5OB02515J

The cascade oxidative annulation reactions of aryl imidazoles with two molecules of alkynes via multiple C–H activation proceed efficiently in the presence of [Cp*RhCl2]2 and Cu(OAc)2·H2O to give substituted benzo[ij]imidazo[2,1,5-de]quinolizine-based polyheteroaromatic compounds. This method is compatible with various functional groups, which are very useful for further synthetic transformations.

Synthesis, structures, and norbornene polymerization behavior of palladium methyl complexes bearing N-heterocyclic carbene-sulfonate ligands

Co-reporter:Minliang Li, Haibin Song, Baiquan Wang

Journal of Organometallic Chemistry 2016 Volume 804() pp:118-122

Publication Date(Web):15 February 2016

DOI:10.1016/j.jorganchem.2015.12.045

•Four NHC-sulfonate palladium methyl complexes were synthesized.•They showed excellent catalytic activities in the polymerization of norbornene.•The highest catalytic activity was up to 108 g of PNB (mol of Pd)−1 h−1.A series of N-heterocyclic carbene-sulfonate (NHC-sulfonate) palladium methyl complexes 2a−d were synthesized from the reaction of NHC-sulfonate ligands with Ag2O and Pd2(μ-Cl)2Me2(2,6-lutidine)2 in good yields. All these complexes were fully characterized by 1H and 13C NMR, elemental analysis, and high-resolution mass spectrometry (HRMS). The molecular structure of the representative complex 2a was also determined by single-crystal X-ray diffraction analysis. Upon activation with either methylaluminoxane (MAO) or [Ph3C]+[B(C6F5)4]−, all the palladium methyl complexes showed excellent catalytic activities [up to 108 g of polynorbornene (PNB) (mol of Pd)−1 h−1] in the vinyl polymerization of norbornene.A series of N-heterocyclic carbene-sulfonate palladium methyl complexes were synthesized. Upon activation with either methylaluminoxane or [Ph3C]+[B(C6F5)4]−, all the palladium methyl complexes showed excellent catalytic activities [up to 108 g of polynorbornene (PNB) (mol of Pd)−1 h−1] in the vinyl polymerization of norbornene.

Rh(III)-Catalyzed C7-Thiolation and Selenation of Indolines

Co-reporter:Wucheng Xie, Bin Li, and Baiquan Wang

The Journal of Organic Chemistry 2016 Volume 81(Issue 2) pp:396-403

Publication Date(Web):December 19, 2015

DOI:10.1021/acs.joc.5b01943

The rhodium(III)-catalyzed intermolecular C7-thiolation and selenation of indolines with disulfides and diselenides were developed. This protocol relies on the use of a removable pyrimidyl directing group to access valuable C-7 functionalized indoline scaffolds with ample substrate scope and broad functional group tolerance.

Synthesis, Structures, and Norbornene Polymerization Behavior of Palladium Complexes Bearing Tridentate o-Aryloxide-N-heterocyclic Carbene Ligands

Co-reporter:Dandan Yang, Yungang Tang, Haibin Song, and Baiquan Wang

Organometallics 2016 Volume 35(Issue 10) pp:1392-1398

Publication Date(Web):January 21, 2016

DOI:10.1021/acs.organomet.5b01006

A series of new pincer-type tridentate o-aryloxide-N-heterocyclic carbene ligands 2a–d were synthesized. Treatment of the proligands with Ag2O and (COD)PdCl2 afforded the desired o-aryloxide-NHC tridentate palladium complexes 3a–d in high yields (NHC = N-heterocyclic carbene). In comparison with the above tridentate complexes, bidentate bis(aryloxide-NHC) palladium complex 3e was also synthesized. All of these complexes were fully characterized by 1H and 13C NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. The molecular structures of 3a,b,d,e were determined by single-crystal X-ray diffraction analysis. On activation with either methylaluminoxane (MAO) or diethylaluminum chloride (Et2AlCl), all palladium complexes exhibited excellent activities of up to 5.99 × 107 g of PNB (mol of Pd)−1 h–1 toward norbornene addition polymerization, and the monomer conversion is up to 99.9%. Notably, the tridentate palladium complexes show better activities than the corresponding bidentate bis(aryloxide-NHC) palladium complexes in the presence of MAO. The resulting polymers were soluble in CHCl3 when the reactions were conducted in the presence of Et2AlCl and were characterized by gel permeation chromatography (GPC).

Ir(III)-Catalyzed Oxidative Coupling of NH Isoquinolones with Benzoquinone

Co-reporter:Tao Zhou, Liubo Li, Bin Li, Haibin Song, and Baiquan Wang

Organic Letters 2015 Volume 17(Issue 17) pp:4204-4207

Publication Date(Web):August 19, 2015

DOI:10.1021/acs.orglett.5b01974

The oxidative coupling reactions of NH isoquinolones with 1,4-benzoquinone proceeded efficiently to form spiro compounds in the presence of an Ir(III) catalyst through C–H activation. The reactions have a broad range of substrates, with nearly quantitative yields, without the use of external oxidants. For 1,4-naphthoquinone and other substituted 1,4-benzoquinone substrates the reactions also gave high yields with Cu(OAc)2·H2O as an external oxidant. A catalytically competent five-membered iridacycle has been isolated and structurally characterized, thus revealing a key intermediate in the catalytic cycle.

Ru(II)-catalyzed amidation reactions of 8-methylquinolines with azides via C(sp3)–H activation

Co-reporter:Bingxian Liu, Bin Li and Baiquan Wang

Chemical Communications 2015 vol. 51(Issue 91) pp:16334-16337

Publication Date(Web):10 Sep 2015

DOI:10.1039/C5CC06230F

Ru(II)-catalyzed amidation reactions of 8-methylquinolines with azides have been developed. They are the first examples of [(p-cymene)RuCl2]2-catalyzed C(sp3)–H bond intermolecular amidation reactions which give quinolin-8-ylmethanamines under mild reaction conditions in good yields.

Regioselective synthesis of multisubstituted isoquinolones and pyridones via Rh(III)-catalyzed annulation reactions

Co-reporter:Liangliang Shi, Ke Yu and Baiquan Wang

Chemical Communications 2015 vol. 51(Issue 97) pp:17277-17280

Publication Date(Web):06 Oct 2015

DOI:10.1039/C5CC05977A

A mild and efficient Rh(III)-catalyzed regioselective synthesis of isoquinolones and pyridones has been developed. The protocol uses readily available N-methoxybenzamide or N-methoxymethacrylamide and diazo compounds as starting materials. The process involving tandem C–H activation, cyclization, and condensation steps proceeds under mild conditions, and the corresponding isoquinolone and pyridone derivatives were obtained in good to excellent yields with excellent regioselectivities. The process provides a facile approach for the construction of isoquinolone and pyridone derivatives containing various functional groups.

Ruthenium(II)-Catalyzed Oxidative Annulation Reactions of Arylimidazolium Salts via N-Heterocyclic Carbene-Directed CH Activation

Co-reporter:Renhe Li;Yang Hu;Ran Liu;Ruofang Hu;Bin Li

Advanced Synthesis & Catalysis 2015 Volume 357( Issue 18) pp:3885-3892

Publication Date(Web):

DOI:10.1002/adsc.201500788

Rhodium(III)-catalyzed cascade oxidative annulation reactions of aryl imidazolium salts with alkynes involving multiple C–H bond activation

Co-reporter:Qingmei Ge, Bin Li, Haibin Song and Baiquan Wang

Organic & Biomolecular Chemistry 2015 vol. 13(Issue 28) pp:7695-7710

Publication Date(Web):05 Jun 2015

DOI:10.1039/C5OB00823A

The cascade oxidative annulation reactions of aryl imidazolium salts with alkynes proceed efficiently in the presence of [Cp*RhCl2]2 and Cu(OAc)2·H2O to give substituted imidazo[1,2-a]-quinolinium salts and benzo[ij]imidazo[2,1,5-de]quinolizinium salts. The reactions were through the normal and abnormal N-heterocyclic carbene (NHC)-directed cyclometalation, alkyne insertion into the Rh–C bond, and reductive elimination of alkenyl and NHC ligands. The reactions are highly regioselective with unsymmetrical alkynes and can be achieved stepwise by controlling the reaction conditions. This provides a new application of NHCs as directing groups and substrates in the synthesis of fused N-heterocyclic compounds. The N-substituting group of the benzo[ij]imidazo[2,1,5-de]quinolizinium salts could be removed successfully with pyridine to afford benzo[ij]imidazo[2,1,5-de]quinolizines in excellent yields. Moreover, some of the benzo[ij]imidazo[2,1,5-de]quinolizinium salts exhibit intense fluorescence which might be useful in organic electronic materials.

Synthesis and Structures of N-Heterocyclic CarbeneSulfonate Ruthenium Complexes and Their Applications in the Ring-Opening Metathesis Polymerization of Norbornene

Co-reporter:Minliang Li;Haibin Song

European Journal of Inorganic Chemistry 2015 Volume 2015( Issue 24) pp:4055-4061

Publication Date(Web):

DOI:10.1002/ejic.201500499

Abstract

A series of N-heterocyclic carbene–sulfonate (NHC–sulfonate) p-cymene ruthenium complexes (2a–2d) were synthesized in high yields from the reactions of NHC–sulfonate ligands with Ag₂O and [(p-cymene)RuCl₂]₂. All of the complexes were characterized fully by ¹H and ¹³C NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. The molecular structures of 2b and 2d were determined by single-crystal X-ray diffraction analysis. Upon activation with Et₂AlCl, the ruthenium complexes 2a–2d showed excellent activities for the ring-opening metathesis polymerization of norbornene and produced polymers with high molecular weights and narrow molecular weight distributions. Complex 2a can also efficiently catalyze the copolymerization of norbornene and cyclooctene. All of the obtained polymers were characterized by ¹H and ¹³C NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC).

Pd/C-Catalyzed Synthesis of Isoquinolones through CH Activation

Co-reporter:Zhen Shu;Dr. Wei Li;Dr. Baiquan Wang

ChemCatChem 2015 Volume 7( Issue 4) pp:605-608

Publication Date(Web):

DOI:10.1002/cctc.201403059

Abstract

The direct synthesis of isoquinolones from benzamides and alkynes through CH activation was developed by using Pd/C as a heterogeneous catalyst without a ligand under mild conditions. A variety of isoquinolones were obtained in good yields with excellent regioselectivities. The Pd/C catalyst could be recycled three times without a significant decrease in the activity (yields as high as 85 %).

Synthesis, Structures, and Norbornene Polymerization Behavior of N-Heterocyclic Carbene-Sulfonate-Ligated Palladacycles

Co-reporter:Minliang Li, Haibin Song, and Baiquan Wang

Organometallics 2015 Volume 34(Issue 10) pp:1969-1977

Publication Date(Web):May 12, 2015

DOI:10.1021/acs.organomet.5b00214

A series of new N-heterocyclic carbene-sulfonate (NHC-sulfonate) ligands 5a–e were synthesized. Treatment of the NHC-sulfonate ligands with Ag2O and palladacycles {[Pd(OAc)(8-Me-quin-H)]2 or [Pd(dmba)(μ-Cl)]2 (dmba = Me2NCH2C6H5)} yielded the desired C(sp3),N-chelated and C(sp2),N-chelated NHC-sulfonate palladacycles 6a–e and 7a–e in high yields. All these complexes were fully characterized by 1H and 13C NMR, high-resolution mass spectrometry, and elemental analysis. The molecular structures of compounds 5a, 6d, 6e, and 7e were determined by single-crystal X-ray diffraction analysis. In the presence of MAO, the C(sp3),N-chelated NHC-sulfonate palladacycles 6a–e showed excellent catalytic activities [107 g of polynorbornene (PNB) (mol of Pd)−1 h–1], while the C(sp2),N-chelated palladacycles 7a–e showed moderate catalytic activities [106 g of PNB (mol of Pd)−1 h–1] in the vinyl polymerization of norbornene. The C(sp2),N-chelated palladacycles 7a–e showed high thermal stability and reached the highest activities at high temperature (100 °C).

o-Aryloxide-N-heterocyclic Carbenes: Efficient Synthesis of the Proligands and Their p-Cymene Ruthenium Complexes

Co-reporter:Dandan Yang, Yungang Tang, Haibin Song, and Baiquan Wang

Organometallics 2015 Volume 34(Issue 10) pp:2012-2017

Publication Date(Web):May 15, 2015

DOI:10.1021/acs.organomet.5b00256

An efficient method to synthesize o-hydroxyaryl-substituted imidazoles (2-OH-3-R-5-tBuC6H2)(C3H3N2) [R = tBu (1a), H (1b)] was developed through copper-catalyzed C–N bond formation. Treatment of 1a or 1b with a halohydrocarbon in refluxing toluene afforded a series of o-hydroxyaryl imidazolinium proligands 2a–h in high yields. Reactions of proligands 2a–h with Ag2O and [(p-cymene)RuCl2]2 gave the corresponding o-aryloxide-N-heterocyclic carbene ligated p-cymene ruthenium complexes 3a–h. All the imidazolium salts and ruthenium complexes were fully characterized by 1H and 13C NMR spectra, elemental analysis, and high-resolution mass spectrometry. Without the cocatalyst or irradiation, these complexes can efficiently catalyze norbornene ring-opening metathesis polymerization. Notably, the structures of the catalysts were found to have significant effects on the catalytic activity and the properties of obtained polymers.

Rhodium(III)-Catalyzed C–H Activation and Annulation with 1-Alkynylphosphine Sulfides: A Mild and Regioselective Access for the Synthesis of Bulky Phosphine Ligands

Co-reporter:Bin Li, Jie Yang, Hong Xu, Haibin Song, and Baiquan Wang

The Journal of Organic Chemistry 2015 Volume 80(Issue 24) pp:12397-12409

Publication Date(Web):November 23, 2015

DOI:10.1021/acs.joc.5b02265

We reported herein rhodium(III)-catalyzed C–H activation and annulation reactions for the synthesis of bulky phosphine ligands by using 1-alkynylphosphine sulfides as key starting materials. In the presence of [Cp*RhCl2]2 (5 mol %) and CsOAc (2.0 equiv), various N-(pivaloyloxy)benzamides (3.0 equiv) could react smoothly with 1-alkynylphosphine sulfides at 40 °C in MeOH/CF3CH2OH cosolvent without external oxidant. Using [CpPhRhCl2]2 as catalyst, the reaction can be performed under less loading of benzamides (2.0 equiv) and milder reaction conditions (25 °C) with higher regioselectivity. In a sequential cyclization/desulfidation process, this new method provides a variety of bulky heteroarylphosphines with an isoquinolin-1(2H)-one motif.

Rh(III)-catalyzed synthesis of 1-aminoindole derivatives from 2-acetyl-1-arylhydrazines and diazo compounds in water

Co-reporter:Yujie Liang, Ke Yu, Bin Li, Shansheng Xu, Haibin Song and Baiquan Wang

Chemical Communications 2014 vol. 50(Issue 46) pp:6130-6133

Publication Date(Web):14 Apr 2014

DOI:10.1039/C4CC01520G

A novel and direct approach to synthesize 1-aminoindole derivatives by Rh(III)-catalyzed cyclization of 2-acetyl-1-arylhydrazines with diazo compounds via aryl C–H activation has been developed. This intermolecular annulation involving tandem C–H activation, cyclization and condensation steps proceeds efficiently in water, obviates the need of external oxidants, and displays a broad substituent scope.

Synthesis, structures, and norbornene polymerization behavior of C(sp3), N-chelated palladacycles bearing o-aryloxide-N-heterocyclic carbene ligands

Co-reporter:Liang Dang, Jing Guo, Haibin Song, Binyuan Liu and Baiquan Wang

Dalton Transactions 2014 vol. 43(Issue 45) pp:17177-17183

Publication Date(Web):24 Sep 2014

DOI:10.1039/C4DT02198C

Treatment of the o-hydroxyaryl imidazolium pro-ligands (2-OH-3,5-tBu2C6H2)(R)(C3H3N2)+Br− [R = Mes (1a), Ph (1b), iPr (1c), Me (1d)] with Ag2O afforded the corresponding silver complexes 2a–d. Subsequent metal-exchange reactions of 2a–d with [Pd(OAc)(8-Me-quin-H)]2 (3) yielded the desired C(sp3), N-chelated and o-aryloxide-NHC-ligated palladacycle complexes 4a–d in 60–80% yields. When the N-tert-butyl substituted o-hydroxyaryl imidazolium pro-ligand 1e reacted with 3 in the presence of K2CO3 in dioxane, the palladacycle complex 4e, in which the NHC adopted an abnormal binding (C4-bonding), was obtained in 20% yield. All these complexes were fully characterized using 1H and 13C NMR spectra, high-resolution mass spectrometry (HRMS), and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures of 4a–c and the abnormal binding of NHC in 4e. With methylaluminoxane (MAO) as the cocatalyst these palladacycles showed excellent catalytic activities of up to 107 g of PNB (mol of Pd)−1 h−1 in the addition polymerization of norbornene.

Rhodium(III)-Catalyzed Alkenylation Reactions of 8-Methylquinolines with Alkynes by C(sp3)H Activation

Co-reporter:Bingxian Liu;Tao Zhou;Dr. Bin Li; Shansheng Xu;Dr. Haibin Song;Dr. Baiquan Wang

Angewandte Chemie 2014 Volume 126( Issue 16) pp:4275-4279

Publication Date(Web):

DOI:10.1002/ange.201310711

Abstract

The alkenylation reactions of 8-methylquinolines with alkynes, catalyzed by [{Cp*RhCl₂}₂], proceeds efficiently to give 8-allylquinolines in good yields by C(sp³)H bond activation. These reactions are highly regio- and stereoselective. A catalytically competent five-membered rhodacycle has been structurally characterized, thus revealing a key intermediate in the catalytic cycle.

Rhodium(III)-Catalyzed Alkenylation Reactions of 8-Methylquinolines with Alkynes by C(sp3)H Activation

Co-reporter:Bingxian Liu;Tao Zhou;Dr. Bin Li; Shansheng Xu;Dr. Haibin Song;Dr. Baiquan Wang

Angewandte Chemie International Edition 2014 Volume 53( Issue 16) pp:4191-4195

Publication Date(Web):

DOI:10.1002/anie.201310711

Abstract

Synthesis, Structures, and Norbornene Polymerization Behavior of o-Aryloxide-Substituted NHC-Ligated σ, π-Cycloalkenyl Palladium Complexes

Co-reporter:Liang Dang, Haibin Song, and Baiquan Wang

Organometallics 2014 Volume 33(Issue 23) pp:6812-6818

Publication Date(Web):November 21, 2014

DOI:10.1021/om500839w

Treatment of the pro-ligand (2-OH-3,5-tBu2C6H2)(Mes)(C3H3N2)+Br– (2a) with di[μ-chloro-2η2,5η1-(6-methoxy-endo-bicyclo[2.2.1]-hept-2-enyl)palladium(II)] (1a) and K2CO3 in dioxane, or reaction of the pro-ligand 2a subsequently with nBuLi and 1a in THF afforded the o-aryloxide-substituted NHC-ligated σ, π-cycloalkenyl palladium complex 3. Similarly, treatment of the pro-ligands (2-OH-3,5-tBu2C6H2)(R)(C3H3N2)+Br– [R = Mes (2a), Me (2b), iPr (2c), Ph (2d)] with bis[μ-chloro-1η2,5η1-(6-ethoxy-exo-5,6-dihydrodicyclopentadienyl)palladium(II)] (1b) and K2CO3 in dioxane afforded the desired products 4–9. All these complexes were fully characterized by 1H and 13C NMR, high-resolution mass spectrometry (HRMS), and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures of 3–6. With methylaluminoxane (MAO) as cocatalyst, these complexes showed excellent catalytic activities up to 107 g of PNB (mol of Pd) –1 h–1 in the addition polymerization of norbornene.

Synthesis and Alkyne Insertion Reactions of NHC-Based Cyclometalated Ruthenium(II) Complexes

Co-reporter:Chong Ma, Chunjin Ai, Zhefu Li, Bin Li, Haibin Song, Shansheng Xu, and Baiquan Wang

Organometallics 2014 Volume 33(Issue 19) pp:5164-5172

Publication Date(Web):September 9, 2014

DOI:10.1021/om500369g

The series of NHC-based cyclometalated ruthenium(II) complexes 2a–k were synthesized by the reactions of aryl-substituted imidazolium salts with [(p-cymene)RuCl2]2 under mild conditions. These complexes could react with alkynes in MeOH at 80 °C, through alkyne insertion and subsequent reductive elimination, to give the new kinds of imidazolium salts 3a–q in high yields. All new compounds were fully characterized, and the molecular structures of 2a–d,f,g,i–k were determined by single-crystal X-ray diffraction analysis.

Palladium-Catalyzed Direct Dehydrogenative Annulation of Ferrocenecarboxamides with Alkynes in Air

Co-reporter:Wucheng Xie, Bin Li, Shansheng Xu, Haibin Song, and Baiquan Wang

Organometallics 2014 Volume 33(Issue 9) pp:2138-2141

Publication Date(Web):April 22, 2014

DOI:10.1021/om5002606

A novel method to synthesize racemic ferrocene[1,2-c]pyridine-3(4H)-ones via Pd-catalyzed direct dehydrogenative annulations of ferrocenecarboxamides with internal alkynes in air has been developed. Both alkyl and aryl ferrocenecarboxamides can be applied as effective substrates.

Regioselective Ortho Olefination of Aryl Sulfonamide via Rhodium-Catalyzed Direct C–H Bond Activation

Co-reporter:Weijia Xie, Jie Yang, Baiquan Wang, and Bin Li

The Journal of Organic Chemistry 2014 Volume 79(Issue 17) pp:8278-8287

Publication Date(Web):August 2, 2014

DOI:10.1021/jo5015239

Rh(III)-catalyzed ortho C–H olefination of aryl sulfonamide directed by the SO2NHAc group is reported. This oxidative coupling process is achieved highly efficiently and selectively with a broad substrate scope. The reactions of N-tosylacetamide with acrylate esters afford ortho-alkenylated benzofused five-membered cyclic sulfonamides, whereas styrenes provide the direct diolefination products.

Rhodium(III)-Catalyzed Intermolecular Amidation with Azides via C(sp3)–H Functionalization

Co-reporter:Nuancheng Wang, Renhe Li, Liubo Li, Shansheng Xu, Haibin Song, and Baiquan Wang

The Journal of Organic Chemistry 2014 Volume 79(Issue 11) pp:5379-5385

Publication Date(Web):May 7, 2014

DOI:10.1021/jo5008515

The amidation reactions of 8-methylquinolines with azides catalyzed by a cationic rhodium(III) complex proceed efficiently to give quinolin-8-ylmethanamine derivatives in good yields via C(sp3)–H bond activation under external oxidant-free conditions. A catalytically competent five-membered rhodacycle has been isolated and characterized, revealing a key intermediate in the catalytic cycle.

Ruthenium-Catalyzed Pyrrole Synthesis via Oxidative Annulation of Enamides and Alkynes

Co-reporter:Bin Li, Nuancheng Wang, Yujie Liang, Shansheng Xu, and Baiquan Wang

Organic Letters 2013 Volume 15(Issue 1) pp:136-139

Publication Date(Web):December 12, 2012

DOI:10.1021/ol303159h

An efficient and regioselective ruthenium-catalyzed oxidative annulation of enamides with alkynes via the cleavage of C(sp2)–H/N–H bonds is reported. The reactions can afford N-acetyl substituted or N-unsubstituted pyrroles by altering the reaction conditions slightly.

Regio- and Stereoselective Olefination of Phenol Carbamates through CH Bond Functionalization

Co-reporter:Bin Li;Jianfeng Ma;Yujie Liang;Nuancheng Wang;Shansheng Xu;Haibin Song

European Journal of Organic Chemistry 2013 Volume 2013( Issue 10) pp:1950-1962

Publication Date(Web):

DOI:10.1002/ejoc.201201574

Abstract

Two pathways that can be used to access ortho-olefinated phenol carbamate, including a ruthenium(II)-catalyzed oxidative olefination of phenol carbamate with acrylates and a rhodium(III)-catalyzed alkyne hydroarylation of phenol carbamate with internal alkynes through direct C–H activation, are reported. Both reactions afford substituted alkenes in a highly regio- and stereoselective manner.

Ruthenium Ring-Opening Metathesis Polymerization Catalysts Bearing o- Aryloxide-N-Heterocyclic Carbenes

Co-reporter:Yong Kong;Yungang Tang;Zunzhi Wang;Shansheng Xu;Haibin Song

Macromolecular Chemistry and Physics 2013 Volume 214( Issue 4) pp:492-498

Publication Date(Web):

DOI:10.1002/macp.201200509

Abstract

A series of o-aryloxide-N-heterocyclic carbene ruthenium complexes 2–4 is synthesized via sequential reactions of the o-hydroxyaryl imidazolium proligands (2-OH-3,5-^tBu₂C₆H₂)(R)(C₃H₃N₂)⁺Br⁻ (R = Me (1a), ⁱPr (1b), Mes (1c)) with Ag₂O and [(C₆H₆)RuCl₂]₂. All of the complexes are characterized by ¹H and ¹³C NMR spectroscopy, high-resolution mass spectrometry (HRMS), and elemental analysis. The molecular structure of 2 is determined by single-crystal X-ray diffraction analysis. The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with 2–4 is studied. Among them, complex 4 exhibits the highest activity and efficiency toward ROMP of NBE at 85 °C without any cocatalyst, and the resultant polymers have very high molecular weight (>10⁶ Da) and narrow molecular weight distributions. This complex can also efficiently catalyze the alternating copolymerization of NBE and cyclooctene.

Regioselective C2 Oxidative Olefination of Indoles and Pyrroles through Cationic Rhodium(III)-Catalyzed CH Bond Activation

Co-reporter:Dr. Bin Li;Jianfeng Ma;Weijia Xie;Dr. Haibin Song; Shansheng Xu;Dr. Baiquan Wang

Chemistry - A European Journal 2013 Volume 19( Issue 36) pp:11863-11868

Publication Date(Web):

DOI:10.1002/chem.201301987

Investigation and Comparison of the Mechanistic Steps in the [(Cp*MCl2)2] (Cp*=C5Me5; M=Rh, Ir)-Catalyzed Oxidative Annulation of Isoquinolones with Alkynes

Co-reporter:Nuancheng Wang;Dr. Bin Li;Dr. Haibin Song; Shansheng Xu;Dr. Baiquan Wang

Chemistry - A European Journal 2013 Volume 19( Issue 1) pp:358-364

Publication Date(Web):

DOI:10.1002/chem.201203374

Abstract

The mechanism of the [(Cp*MCl₂)₂] (M=Rh, Ir)-catalyzed oxidative annulation reaction of isoquinolones with alkynes was investigated in detail. In the first acetate-assisted CH-activation process (cyclometalated step) and the subsequent mono-alkyne insertion into the MC bonds of the cyclometalated compounds, both Rh and Ir complexes participated well. However, the desired final products, dibenzo[a,g]quinolizin-8-one derivatives, were only formed in high yield when the Rh species participated in the final oxidative coupling of the CN bond. Moreover, a Rh^I sandwich intermediate was isolated during this transformation. The iridium complexes were found to be inactive in the oxidative coupling processes. All of the relevant intermediates were fully characterized and determined by single-crystal X-ray diffraction analysis. Based on this mechanistic study, a Rh^IIIRh^IRh^III catalytic cycle was proposed for this reaction.

Photochemical C–H activation and subsequent aerobic oxidation reactions of benzene with Cp*Ir(CO)2

Co-reporter:Xing Tan, Bin Li, Shansheng Xu, Haibin Song, Baiquan Wang

Journal of Organometallic Chemistry 2013 735() pp: 72-79

Publication Date(Web):

DOI:10.1016/j.jorganchem.2013.03.014

Ruthenium-Catalyzed Regioselective C2 Alkenylation of Indoles and Pyrroles via C–H Bond Functionalization

Co-reporter:Bin Li, Jianfeng Ma, Weijia Xie, Haibin Song, Shansheng Xu, and Baiquan Wang

The Journal of Organic Chemistry 2013 Volume 78(Issue 18) pp:9345-9353

Publication Date(Web):August 28, 2013

DOI:10.1021/jo401579m

An efficient ruthenium-catalyzed oxidative coupling of indoles and pyrroles with various alkenes at the C2-position assisted by employing the N,N-dimethylcarbamoyl moiety as a directing group is reported. The catalytic reaction proceeds in an excellent regio- and stereoselective manner.

Synthesis, Reactivities, and Catalytic Properties of Iodo-Bridged Polymeric Iridium Complexes with Flexible Carbon Chain-Bridged Bis(tetramethylcyclopentadienyl) Ligands

Co-reporter:Xing Tan, Bin Li, Shansheng Xu, Haibin Song, and Baiquan Wang

Organometallics 2013 Volume 32(Issue 11) pp:3253-3261

Publication Date(Web):May 24, 2013

DOI:10.1021/om4001742

Dinuclear iridium complexes [(C5Me4)(CH2)n(C5Me4)][Ir(COD)]2 (2a: n = 2; 2b: n = 3; 2c: n = 4) are obtained from the reactions of the corresponding dilithium salts Li2[(C5Me4)(CH2)n(C5Me4)] (n = 2–4) with [Ir(μ-Cl)(COD)]2. Further oxidation of 2 affords iodo-bridged polymeric iridium complexes [(C5Me4)(CH2)n(C5Me4)(IrI2)2]m (3a: n = 2; 3b: n = 3; 3c: n = 4). Dinuclear iridium complexes [(C5Me4)(CH2)n(C5Me4)][IrI2(PPh3)]2 (4a: n = 2; 4b: n = 3; 4c: n = 4) and [(C5Me4)(CH2)n(C5Me4)][IrI2(CO)]2 (5b: n = 3; 5c: n = 4) are obtained from the reactions of 3 with PPh3 and CO, respectively. Dinuclear dicarbonyl iridium complexes [(C5Me4)(CH2)n(C5Me4)][Ir(CO)2]2 (6b: n = 3; 6c: n = 4) are obtained from the reactions of 3 with Zn and CO. Additionally, the cyclometalated dinuclear iridium complexes 7b,c, 8b,c, 9b,c, and 10b,c are obtained from the reactions of 3 with the corresponding nitrogen ligands in the presence of KOH. The molecular structures of complexes 2a, 4a, 5b, 6c, and 7b have been determined by single-crystal X-ray diffraction analysis. Moreover, we found that complexes 3 and 4 are efficient catalysts for the selective amine cross-coupling reaction.

Rhodium-Catalyzed Cascade Oxidative Annulation Leading to Substituted Naphtho[1,8-bc]pyrans by Sequential Cleavage of C(sp2)–H/C(sp3)–H and C(sp2)–H/O–H Bonds

Co-reporter:Xing Tan ; Bingxian Liu ; Xiangyu Li ; Bin Li ; Shansheng Xu ; Haibin Song

Journal of the American Chemical Society 2012 Volume 134(Issue 39) pp:16163-16166

Publication Date(Web):September 19, 2012

DOI:10.1021/ja3075242

The cascade oxidative annulation reactions of benzoylacetonitrile with internal alkynes proceed efficiently in the presence of a rhodium catalyst and a copper oxidant to give substituted naphtho[1,8-bc]pyrans by sequential cleavage of C(sp2)–H/C(sp3)–H and C(sp2)–H/O–H bonds. These cascade reactions are highly regioselective with unsymmetrical alkynes. Experiments reveal that the first-step reaction proceeds by sequential cleavage of C(sp2)–H/C(sp3)–H bonds and annulation with alkynes, leading to 1-naphthols as the intermediate products. Subsequently, 1-naphthols react with alkynes by cleavage of C(sp2)–H/O–H bonds, affording the 1:2 coupling products. Moreover, some of the naphtho[1,8-bc]pyran products exhibit intense fluorescence in the solid state.

Ruthenium-Catalyzed Oxidative C–H Bond Olefination of N-Methoxybenzamides Using an Oxidizing Directing Group

Co-reporter:Bin Li, Jianfeng Ma, Nuancheng Wang, Huiliang Feng, Shansheng Xu, and Baiquan Wang

Organic Letters 2012 Volume 14(Issue 3) pp:736-739

Publication Date(Web):January 18, 2012

DOI:10.1021/ol2032575

Ruthenium-catalyzed oxidative C–H bond olefination of N-methoxybenzamides using an oxidizing directing group with a broad substrate scope is reported. The reactions of N-methoxybenzamides with acrylates in MeOH and styrene (or norbornadiene) in CF3CH2OH afforded two types of products.

Ruthenium-Catalyzed Oxidative Coupling/Cyclization of Isoquinolones with Alkynes through CH/NH Activation: Mechanism Study and Synthesis of Dibenzo[a,g]quinolizin-8-one Derivatives

Co-reporter:Dr. Bin Li;Huiliang Feng;Nuancheng Wang;Jianfeng Ma;Dr. Haibin Song; Shansheng Xu;Dr. Baiquan Wang

Chemistry - A European Journal 2012 Volume 18( Issue 40) pp:12873-12879

Publication Date(Web):

DOI:10.1002/chem.201201862

Abstract

The mechanism of [{RuCl₂(p-cymene)}₂]-catalyzed oxidative annulations of isoquinolones with alkynes was investigated in detail. The first step is an acetate-assisted CH bond activation process to form cyclometalated compounds. Subsequent mono-alkyne insertion of the RuC bonds of the cyclometalated compounds then takes place. Finally, oxidative coupling of the CN bond of the insertion compounds occurs to afford Ru⁰ sandwich complexes that undergo oxidation to regenerate the catalytically active Ru^II complex with the copper oxidant and release the desired dibenzo[a,g]quinolizin-8-one derivatives. All of the relevant intermediates were fully characterized and determined by single crystal X-ray diffraction analysis. The [{RuCl₂(p-cymene)}₂]-catalyzed CH bond functionalization of isoquinolones with alkynes to synthesize dibenzo[a,g]quinolizin-8-one derivatives through CH/NH activation was also demonstrated.

Synthesis, Structures, and Norbornene ROMP Behavior of o-Aryloxide-N-Heterocyclic Carbene p-Cymene Ruthenium Complexes

Co-reporter:Yong Kong ; Shansheng Xu ; Haibin Song

Organometallics 2012 Volume 31(Issue 15) pp:5527-5532

Publication Date(Web):July 16, 2012

DOI:10.1021/om300474n

Treatment of the o-hydroxyaryl imidazolium proligands (2-OH-3,5-tBu2C6H2)(R)(C3H3N2)+Br– (R = iPr (1a), tBu (1b), Ph (1c), Mes (1d)) with 3 equiv of Ag2O afforded the corresponding silver complexes 2a–d. The subsequent metal-exchange reactions with [(p-cymene)RuCl2]2 at room temperature yielded the desired o-aryloxide-N-heterocyclic carbene p-cymene ruthenium complexes 3a–d in nearly quantitative yields. All the complexes were characterized by 1H and 13C NMR, high-resolution mass spectrometry (HRMS), and elemental analysis. The molecular structure of complex 3b was determined by single-crystal X-ray diffraction analysis. The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with 3a–d was studied. Among them, complex 3d showed high activity and efficiency toward ROMP of NBE at 85 °C without the need for any cocatalyst, and polymers with very high molecular weight (>106) and narrow molecular weight distributions were obtained. This complex can also catalyze the alternating copolymerization of NBE and cyclooctene (COE).

Reactions of Unsymmetrically Substituted N-Heterocyclic Carbenes with Ru3(CO)12

Co-reporter:Congying Zhang, Bin Li, Haibin Song, Shansheng Xu, and Baiquan Wang

Organometallics 2011 Volume 30(Issue 11) pp:3029-3036

Publication Date(Web):May 9, 2011

DOI:10.1021/om2000647

Reactions of a series of unsymmetrically substituted N-heterocyclic carbene ligands with Ru3(CO)12 afforded a variety of mononuclear (1, 2), trinuclear (3, 4, 5, and 5′), and tetranuclear (6, 7) ruthenium complexes via intramolecular ruthenium-mediated sp2 and sp3 C–H bond activations. Complexes 6 and 7 include an octahedral cluster skeleton consisting of four ruthenium atoms and two metalated carbon atoms. The formation of this type of ruthenium clusters is proposed to involve the initial C–C double-bond migration and subsequent sp2 C–H bond activations. All new complexes were fully characterized, and the molecular structures of 1, 2, 5, 6, and 7 were determined by X-ray diffraction analysis.

Trinuclear and Tetranuclear Ruthenium Carbonyl Clusters Derived from Indenylphosphines: Cleavage of C−H and C−P Bonds

Co-reporter:Xing Tan, Bin Li, Shansheng Xu, Haibin Song, and Baiquan Wang

Organometallics 2011 Volume 30(Issue 8) pp:2308-2317

Publication Date(Web):March 23, 2011

DOI:10.1021/om200072g

Thermal treatment of Ru3(CO)12 with equimolar amounts of (1H-inden-3-yl)diphenylphosphine and (1H-inden-2-yl)diphenylphosphine in octane gave two isomeric trinuclear ruthenium clusters Ru3(μ2-H)(μ3-3-Ph2PC9H6)(CO)9 (1) and Ru3(μ2-H)(μ3-2-Ph2PC9H6)(CO)9 (2), respectively, via a C−H bond cleavage. Heating either 1 or 2 in octane afforded the trinuclear and tetranuclear ruthenium clusters Ru3(μ3-PPh)(μ3-C9H6)(CO)9 (3) and Ru4(μ4-PPh)(μ4-C9H6)(CO)11 (4) via double C−P bond cleavage. Thermal treatment of Ru3(CO)12 with (4,7-dimethyl-1H-inden-3-yl)diphenylphosphine in octane gave trinuclear ruthenium cluster Ru3(μ2-H)(μ3-3-Ph2PC11H10)(CO)9 (5) via a C−H bond cleavage. Heating 5 in octane afforded a trinuclear ruthenium cluster Ru3(μ3-PPh)(μ3-C11H10)(CO)9 (6) and two isomeric tetranuclear ruthenium clusters Ru4(μ3-PPh)(μ2-η5:η1-C11H10)(CO)11 (7) and [Ru4(μ4-PPh)(μ4-C11H10)(CO)11] (8) via double C−P bond cleavage. Thermal treatment of Ru3(CO)12 with (3,4,7-trimethyl-1H-inden-1-yl)diphenylphosphine in toluene afforded two trinuclear ruthenium clusters Ru3(μ2-H)2(μ3-3-Ph2PC12H11)(CO)8 (9) via both sp3 and sp2 C−H bond cleavage and Ru3(μ2-PPh2)(μ3-η2:η2:η5-C12H13)(CO)6 (10) via a C−P bond cleavage. Thermal treatment of Ru3(CO)12 with (3-methyl-1H-inden-1-yl)diphenylphosphine in toluene afforded a trinuclear ruthenium cluster Ru3(μ2-H)(μ3-3-Ph2PC10H8)(CO)9] (11) via a C−H bond cleavage. The molecular structures of complexes 1−5 and 7−11 have been determined by single-crystal X-ray diffraction analysis.

Synthesis, Structures, and Norbornene Polymerization Behavior of Bis(aryloxide-N-heterocyclic carbene) Nickel Complexes

Co-reporter:Yong Kong, Man Cheng, Hongping Ren, Shansheng Xu, Haibin Song, Min Yang, Binyuan Liu, and Baiquan Wang

Organometallics 2011 Volume 30(Issue 6) pp:1677-1681

Publication Date(Web):February 14, 2011

DOI:10.1021/om1011825

Treatment of the o-hydroxyaryl imidazolinium pro-ligands (2-OH-3,5-tBu2C6H2)(R)(C3H3N2)+Br− [R = iPr (1a), tBu (1b), Ph (1c), Mes (1d)] with NiL2Cl2 (L = PPh3, Py) or Ni(OAc)2·4H2O afforded the corresponding cis bis(aryloxide-NHC) nickel complexes 2−5. Notably, the products were independent from the pro-ligands/Ni ratios. The same complexes were obtained with the pro-ligands/Ni ratio of 1:1 or 2:1. All the complexes were characterized by 1H and 13C NMR, high-resolution mass spectrometry (HRMS), and elemental analysis. The molecular structures of the aryloxide-NHC-ligated nickel complexes 2−5 were determined by single-crystal X-ray diffraction analysis. With methylaluminoxane (MAO) as cocatalyst, the nickel complexes showed moderate catalytic activities (106 g of PNB (mol of Ni)−1 h−1) in the addition polymerization of norbornene.

Reactions of a Trinuclear Ruthenium Complex Derived from 3-(2-Pyridyl)indene with Diphenylacetylene and Phenylacetylene: Insertion of Alkynes into the Ru−C bond

Co-reporter:Dafa Chen, Congying Zhang, Shansheng Xu, Haibin Song, and Baiquan Wang

Organometallics 2011 Volume 30(Issue 4) pp:676-683

Publication Date(Web):February 4, 2011

DOI:10.1021/om1008007

Thermal treatment of the trinuclear ruthenium complex {μ2-η5:η1-(C5H4N)(C9H5)}Ru3(CO)9 (1) with 1 equiv of diphenylacetylene gave the trinuclear complex {μ3-η1:η2:η5-(C5H4N)(C9H5)(PhC═CPh)}Ru3(CO)7 (2) via the insertion of an alkyne into the Ru−C(η1) bond of 1. Complex 2 could be transformed into the dinuclear and trinuclear complexes {μ2-η1:η5-(C5H4N)(C9H5)(PhC═CPh)}Ru2(CO)2(μ2-η2:η4-CPh═CPhCPh═CPh) (3), {μ3-η2:η3:η5-(C5H4N)(C9H5)(CPhCPh═CPhCPh)}Ru3(CO)6 (4), and {μ2-η1:η5-(C5H4N)(C9H5)(PhC═CPh)}Ru3(CO)4(μ3-η2-PhC═CPh)2 (5) in the presence of excess diphenylacetylene. Similarly, reaction of 1 with 1 equiv of phenylacetylene gave the alkyne-inserted product {μ3-η1:η2:η5-(C5H4N)(C9H5)(HC═CPh)}Ru3(CO)7 (6), which could also react with excess phenylacetylene to give the complexes {μ3-η2:η4:η5-(C5H4N)(C9H5)(C═CPhCH═CPh)}(μ2-H)Ru3(CO)6 (7) and {μ2-η2:η4-(C5H4N)(C9H6)(C═CPhCH═CPh)}Ru2(CO)4(μ2-CO) (8). Complex 7 could be transformed slowly into 8 in refluxing toluene. The reactions of 3-(2-pyridyl)indene with internal alkynes catalyzed by Ru3(CO)12 and 1 were also tested, obtaining several C−H/alkyne coupling products, while the reaction with phenylacetylene did not work under the same conditions. The molecular structures of 2−8 were determined by X-ray diffraction.

Synthesis, Structures, and Norbornene Polymerization Behavior of Aryloxide-N-Heterocyclic Carbene Ligated Palladacycles

Co-reporter:Yong Kong, Lifang Wen, Haibin Song, Shansheng Xu, Min Yang, Binyuan Liu, and Baiquan Wang

Organometallics 2011 Volume 30(Issue 1) pp:153-159

Publication Date(Web):December 14, 2010

DOI:10.1021/om100994s

Treatment of the o-hydroxyaryl imidazolinium pro-ligands (2-OH-3,5-tBu2C6H2)(R)(C3H3N2)+Br− [R = Me (3a), iPr (3b), tBu (3c), Ph (3d), Mes (3e)] with the palladacycle [Pd(dmba)(μ-Cl)]2 (dmba = Me2NCH2C6H5) (2) afforded the corresponding aryloxide-NHC (NHC = N-heterocyclic carbene)-ligated palladacycles (2-O-3,5-tBu2C6H2)(R)(NHC)Pd(dmba) [R = Me (4), iPr (5), Ph (6), Mes (7), tBu (8)]. Notably, without isolating 2, complexes 4−8 could also be obtained by one-pot, three-component, sequential reaction of N,N-dimethylbenzylamine, PdCl2, and the pro-ligands in refluxing acetonitrile in the presence of K2CO3. When the N-functional group on the NHCs is tert-butyl, the NHC in 8 adopts an abnormal binding (C4-bonding). All these complexes were fully characterized by 1H and 13C NMR, high-resolution mass spectrometry (HRMS), and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures of 4−8 and the abnormal binding of NHC in 8. With methylaluminoxane (MAO) as cocatalyst these palladacycles showed excellent catalytic activities up to 107 g of PNB (mol of Pd) −1 h−1 in the addition polymerization of norbornene.

Ruthenium-Catalyzed Isoquinolone Synthesis through CH Activation Using an Oxidizing Directing Group

Co-reporter:Dr. Bin Li;Huiliang Feng; Shansheng Xu;Dr. Baiquan Wang

Chemistry - A European Journal 2011 Volume 17( Issue 45) pp:12573-12577

Publication Date(Web):

DOI:10.1002/chem.201102445

Alkyne-functionalized metallocene complexes: Synthesis, structure, and catalytic ethylene polymerization

Co-reporter:Min-Xiong Li, Shan-Sheng Xu, Hai-Bin Song, Bin-Yuan Liu, Bai-Quan Wang

Polyhedron 2011 30(7) pp: 1313-1317

Publication Date(Web):

DOI:10.1016/j.poly.2011.02.011

Alkyne-Functionalized Zirconocene Complexes: Synthesis, Structures, and Reactivities

Co-reporter:Minxiong Li, Haibin Song, Shansheng Xu, and Baiquan Wang

Organometallics 2010 Volume 29(Issue 22) pp:6092-6096

Publication Date(Web):October 27, 2010

DOI:10.1021/om1007677

Reactions of (phenylethynyl)lithium with substituted cyclopentenones gave the corresponding phenylethynyl-substituted cyclopentadienes 1,2-R2-4-(PhC≡C)C5H2 (R = Me (1a), Ph (1b)), which underwent subsequent deprotonation and transmetalation with ZrCl4 to yield the corresponding alkyne-functionalized zirconocene complexes {η5-[1,2-R2-4-(PhC≡C)C5H2]}2ZrCl2 (R = Me (2a), Ph (2b)). Thermal treatment of 2a,b with Ru3(CO)12 in refluxing benzene afforded the trinuclear complexes (3,4-R2C5H2)2(μ3-C4Ph2)Ru3(CO)6(μ-CO)2 (R = Me (3a), Ph (3b)) and the dinuclear complex (3,4-Ph2C5H2)2(μ-C4Ph2)Ru2(CO)5(μ-CO) (3c), via the unexpected cleavage of the two Cp′−Zr bonds. The crystal structures of 2b and 3a,c were determined by X-ray diffraction.

Pyridyl-Substituted Indenyl Ruthenium Complexes: Synthesis, Structures, and Reactivities

Co-reporter:Dafa Chen, Xi Zhang, Shansheng Xu, Haibin Song and Baiquan Wang

Organometallics 2010 Volume 29(Issue 15) pp:3418-3430

Publication Date(Web):July 12, 2010

DOI:10.1021/om100556y

We have investigated the synthesis of a novel pyridyl-substituted indenyl trinuclear ruthenium complex, {μ2-η5:η1-(C5H4N)(C9H5)}Ru3(CO)9 (1), and its reactivities with pyridine derivatives, PPh3, and different types of alkenes. Complex 1 was synthesized in 89% yield from Ru3(CO)12 and 3-(2-pyridyl)indene (1:1 mol ratio) in refluxing heptane. The reaction of 1 with a 5-fold excess of 3-(2-pyridyl)indene gave two complexes, {η1-(C5H4N)(C9H6)}2Ru(CO)2 (2) and {η5-(C5H4N)(C9H6)}{η1-(C5H4N)(C9H6)}Ru2(CO)4 (3). Both were also converted back to 1 in the presence of an equimolar amount of Ru3(CO)12, although the yields were low. Reaction of 1 in refluxing toluene afforded an unexpected complex, {μ3-η6:η3:η1-(C5H4N)(C9H5)}Ru3(CO)7 (4), via the loss of two CO groups. Complex 4 represents a completely new type of coordination mode (μ3-η6:η3:η1) of indenyl ligands in transition metal complexes. The reactions of 1 with 2-(2-pyridyl)indene, 1,2,3,5-tetramethyl-4-(2-pyridyl)cyclopentadiene, 1,2-diphenyl-4-(2-pyridyl)cyclopentadiene, and 2-phenylpyridine in refluxing heptane afforded the mono- and/or dinuclear complexes 5−9 via the cleavage of either a Ru−C(η1) or Ru−C(η5) bond or both. In the case of PPh3, only one of three carbonyls at the pyridyl-coordinated ruthenium center of 1 was replaced by PPh3 to produce {μ2-η5:η1-(C5H4N)(C9H5)}Ru3(CO)8(PPh3) (10). The reactions of 1 with various terminal alkenes (CH2═CHR) gave only the dinuclear ruthenium complexes {η5-(C5H4N)(C9H5CHCH2R)}Ru2(CO)5 (11−13, 15, and 17) via the insertion of alkenes into the Ru−C(η1) bond of 1 with the exception of 2-vinylpyridine and CH2═CHOCH2CH3, which reacted with 1 to yield the pyridyl-substituted complex {η5-(C5H4N)(C9H5CHCH2(C5H4N))}Ru2(CO)4 (14) and two unexpected complexes, 13 and {η5-(C5H4N)(C9H4CHCH2CH2CH(OCH2CH3))}Ru2(CO)5 (18a and 18b), respectively. Complex 15 was also transformed to {η5-(C5H4N)(C9H5CHCH2CO2CH3)}Ru2(CO)3(η5-CH2═CHCO2CH3) (16) in the presence of methyl acrylate. The reactions of 1 with internal alkenes such as norbornene and cyclohexene gave complexes 19−22 in very low yields also via the insertion of alkenes into the Ru−C(η1) bond of 1, with the concomitant formation of a small amount of 4. The molecular structures of 1−5, 8−11, 13−16, 18a, 18b, and 21 were determined by X-ray diffraction analysis. An alternative mechanism for the formation of dinuclear ruthenium complexes via the insertion of alkenes into the Ru−C(η1) bond is proposed.

The intramolecular sp2 and sp3 C–H bond activation of (p-cymene)ruthenium(II) N-heterocyclic carbene complexes

Co-reporter:Congying Zhang, Yang Zhao, Bin Li, Haibin Song, Shansheng Xu and Baiquan Wang

Dalton Transactions 2009 (Issue 26) pp:5182-5189

Publication Date(Web):13 May 2009

DOI:10.1039/B818091A

The intramolecular sp2 and sp3 C–H activated products, as well as the monometalated products, based on the “(p-cymene)Ru(NHC)” framework were synthesised by treatment of a series of NHCs (1-R-3-methylimidazol-2-ylidene [R = Ph (1), Bn (2), t-Bu (3), i-Pr (4), Mes (5), Cy (6)] and 1,3-bis(isopropyl)imidazol-2-ylidene (7)) with [(p-cymene)RuCl2]2 under mild conditions. A new NHC precursor (1-tert-butyl-3-phenyl-4,5-dihydro-imidazol-2-ylidene) was also designed to compare the reactivity of sp2 C–H and sp3 C–H bonds upon cyclometalation, and only the sp3 C–H activated product (8) was observed. The factors that possibly determine the selectivity of intramolecular sp2 or sp3 C–H activation are elucidated by a series of experiments. In the cases where activation of both sp2 C–H and sp3 C–H is possible, steric factors overrode the others to dominate the regioselectivity of activation. All complexes were characterised by 1H NMR, 13C NMR and HRMS spectra. The molecular structures of 1, 3, 5, 6, 7, and 8 were confirmed by X-ray diffraction.

Reactions of indenyl-functionalized imidazolium salts and N-heterocyclic carbenes with Ru3(CO)12

Co-reporter:Congying Zhang, Feng Luo, Bin Cheng, Bin Li, Haibin Song, Shansheng Xu and Baiquan Wang

Dalton Transactions 2009 (Issue 35) pp:7230-7235

Publication Date(Web):28 Jul 2009

DOI:10.1039/B906933J

Thermal treatment of indenyl-functionalized imidazolium salts and N-heterocyclic carbenes with Ru3(CO)12 gave different products. The normal mononuclear metal complexes (2a, 2b) were obtained via direct reaction of indenyl-functionalized imidazolium salts (1a, 1b) with Ru3(CO)12. Unexpected intramolecular C–H activated products (3a, 3b, 4a, 4b) were obtained via thermal treatment of corresponding indenyl-functionalized N-heterocyclic carbenes. All complexes were determined by 1H NMR, 13C NMR, IR spectra and elemental analysis. The molecular structures of 2b, 3a, 3b and 4b were determined by X-ray diffraction.

Controlled/“living” radical polymerization of methyl methacrylate catalyzed by CpCo(I) complexes conveniently generated from cobaltocene in situ

Co-reporter:Xi Zhao, Yanqiong Yu, Shansheng Xu, Baiquan Wang

Polymer 2009 50(10) pp: 2258-2263

Publication Date(Web):

DOI:10.1016/j.polymer.2009.03.019

The exo-substituted η4-cyclopentadiene CpCo(I) complexes: A new kind of ATRP catalysts and the actual catalyst for the cobaltocene-catalyzed ATRP

Co-reporter:Xiongxiong Luo, Xi Zhao, Shansheng Xu, Baiquan Wang

Polymer 2009 50(3) pp: 796-801

Publication Date(Web):

DOI:10.1016/j.polymer.2008.12.011

Synthesis, Structures, and Norbornene Polymerization Behavior of Bis(aryloxide-N-heterocyclic carbene) Palladium Complexes

Co-reporter:Yong Kong, Hongping Ren, Shansheng Xu, Haibin Song, Binyuan Liu and Baiquan Wang

Organometallics 2009 Volume 28(Issue 20) pp:5934-5940

Publication Date(Web):September 23, 2009

DOI:10.1021/om900625r

A series of o-hydroxyaryl imidazolinium pro-ligands 3a−3e were synthesized by the reactions of 4-bromo-2,4,6-tri-tert-butyl-2,5-cyclohexadien-1-one (1) with different N-substituted imidazoles. Treatment of the pro-ligands with Pd(OAc)2 afforded the corresponding bis(aryloxide-NHC) palladium complexes (NHC = N-heterocyclic carbene). The N-substituents at the NHCs were found to have significant effects on the structures of the bis(aryloxide-NHC) palladium complexes. Trans isomers were obtained when R = Me and iPr, while cis isomers were obtained for R = Ph and Mes (Mes = mesityl). However, for R = tBu, a cis isomer with a normal and an abnormal NHC ligand was obtained. All these complexes have been characterized by 1H and 13C NMR and HRMS spectroscopy. The molecular structures of the pro-ligand 3b and complexes 4−8 were determined by single-crystal X-ray diffraction analysis. With methylaluminoxane (MAO) as cocatalyst these bis(aryloxide-NHC) palladium complexes showed excellent catalytic activities up to 107 g of PNB (mol of Pd)−1 h−1 in the addition polymerization of norbornene.

Reactions of Dihydrooctamethyl-s-indacene and 1,2,3,4,7-Pentamethylindene with Ru3(CO)12: Intramolecular sp3 C−H Activation

Co-reporter:Kun Xu, Bin Li, Shansheng Xu, Haibin Song and Baiquan Wang

Organometallics 2009 Volume 28(Issue 15) pp:4438-4442

Publication Date(Web):July 17, 2009

DOI:10.1021/om900337h

Thermal treatment of dihydrooctamethyl-s-indacene with Ru3(CO)12 afforded the trinuclear and tetranuclear complexes Ru3(η5:η5:η2-C20H24)(CO)7 (1) and Ru4(η5:η4:η1-C20H24)(μ-CO)2(CO)7 (2), via intramolecular sp3 C−H bond activation, and the mononuclear complex Ru(η5-C20H25)(CO)2Cl (3), which might be formed via chlorination of a terminal hydride complex during column chromatography. Reaction of 1,2,3,4,7-pentamethylindene with Ru3(CO)12 also yielded the tetranuclear complex Ru4(η5:η3:η2-C14H16)(CO)9 (4) via the same sp3 C−H bond activation, together with the dinuclear complex [(η5-C9H2Me5)Ru(CO)]2(μ-CO)2 (5). In contrast, reaction of 4,7-dimethylindene with Ru3(CO)12 gave only the dinuclear complex [(η5-C9H5Me2)Ru(CO)]2(μ-CO)2 (6). The molecular structures of all six complexes have been determined by single-crystal X-ray diffraction analysis.

Diels−Alder Reactions of Benzyne with Indenyl and Fluorenyl Ruthenium Complexes

Co-reporter:Shuang Luo, Xi Zhao, Bin Mu, Haibin Song, Shansheng Xu and Baiquan Wang

Organometallics 2009 Volume 28(Issue 15) pp:4602-4605

Publication Date(Web):July 21, 2009

DOI:10.1021/om9003303

The indenyl ruthenium compound (η5-C9H7)Ru(η5-C5Me5) (1) was found to react with benzyne, generated from o-trimethylsiylphenyl triflate by fluoride-induced 1,2-elimination, to afford the Diels−Alder adduct 1,2-(1,4-dihydronaphthalen-1,4-diyl)pentamethylruthenocene (2). When the bis(indenyl) ruthenium complex (η5-C9H7)2Ru (3) reacted with benzyne, the bisadduct 4 was obtained along with the monoadduct 5. Reaction of fluorenyl ruthenium compound (η5-C13H9)Ru(η5-C9H7) (6) with benzyne gave only the monoadduct 7 and a byproduct, 9,9′-diphenylfluorene (8). The crystal structures of 7 and 8 were determined by X-ray diffraction analysis.

Synthesis, Structures, and Polymerization Catalytic Properties of Doubly Bridged Bis(cyclopentadienyl) Dinuclear (μ-Oxo)titanium Complexes

Co-reporter:Shuang Luo, Bo Shen, Bin Li, Haibin Song, Shansheng Xu and Baiquan Wang

Organometallics 2009 Volume 28(Issue 10) pp:3109-3112

Publication Date(Web):April 23, 2009

DOI:10.1021/om900089w

The doubly bridged dinuclear (μ-oxo)titanium complex (Me2C)(Me2Si)(C5H3)2(μ-O)(CpTiCl)2 (1) was synthesized by the reaction of the lithium compound of the doubly bridged bis(cyclopentadienyl) ligand with (CpTiCl2)2O. Treatment of 1 with concentrated HCl or HBr gave the corresponding Cp-decoordinated products (Me2C)(Me2Si)(C5H3)2[CpTiX(μ-O)TiX2] (X = Cl (2), Br (3)). All these titanium complexes were characterized by 1H NMR, 13C NMR, MS spectra, and elemental analysis. The crystal structures of (CpTiCl2)2O, 1, and 3 were determined by X-ray diffraction. Their catalytic properties for ethylene polymerization were also studied in the presence of MAO.

Synthesis and reactivity of 2-(tert-butylcyclopentadienyl)-indenyl dinuclear ruthenium complex [η5:η5-(tBuC5H3)(C9H6)]Ru2(CO)4: Halogen induced Ru cleavage from indenyl ring

Co-reporter:Bin Li, Xing Tan, Shansheng Xu, Haibin Song, Baiquan Wang

Journal of Organometallic Chemistry 2009 694(9–10) pp: 1503-1508

Publication Date(Web):

DOI:10.1016/j.jorganchem.2008.12.058

Reactions of (Me2C)(Me2Si)[(5-C5H3)Mo(CO)3]2 with Phosphanylalkynes: Rearrangement of Phosphanylalkynes into Phosphido-Substituted Vinylidenyl Ligands by Cleavage of the PC(alkyne) Bond and Formation of a PC(alkene) Bond

Co-reporter:Bin Li;Shansheng Xu;Haibin Song

European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 35) pp:5494-5504

Publication Date(Web):

DOI:10.1002/ejic.200800704

Abstract

This article deals with the thermal reactions of the doubly bridged bis(cyclopentadienyl) dinuclear molybdenum complex (Me₂C)(Me₂Si)[(η⁵-C₅H₃)Mo(CO)₃]₂ (1) with a series of phosphanylalkynes Ph_nP(C≡CR)_3–n (n = 2, 1, 0; R = Ph, Fc). In addition to the complex (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄(μ-η²-η²(⟂)-R¹C≡CR²)] [R¹ = Ph, R² = Ph₂P, 2; R¹ = Ph, R² = Ph₂P(O), 4; R¹ = Ph, R² = PhP(C≡CPh), 6; R¹ = Fc, R² = PhP(C≡CFc), 8; and R¹ = Fc, R² = PhP(O)(C≡CFc), 10], in which the phosphanylalkynes acted as disubstituted acetylenes, the P–C(alkyne) bond cleavage and phosphanylalkyne rearrangement products (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄{μ-η¹-η²-C=C(R¹)R²}] [R¹ = Ph, R² = Ph₂P, 3; R¹ = Fc, R² = Ph₂P, 5; R¹ = Ph, R² = PhP(C≡CPh), 7; and R¹ = Fc, R² = PhP(C≡CPh), 9] were also isolated when mono- and bis(ethynyl)-functionalized phosphanes reacted with 1. Reactions of tris(ethynyl)-functionalized phosphanes with 1 afforded the phosphanylalkyne-bridged complexes (or/andtheir oxide) (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄(μ-η²-η²(⟂)-R¹C≡CR²)] [R¹ = Ph, R² = P(C≡CPh)₂, 11a and 11b; R¹ = Ph, R² = P(O)(C≡CPh)₂, 12; and R¹ = Fc, R² = P(C≡CFc)₂, 13]. All the new complexes were fully characterized. X-ray characterization of 3, 5, 6, 7, 11a, 11b, 13, and P(C≡CFc)₃ are also provided.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Reactions of Pyridyl Side Chain Functionalized Indenes with Ru3(CO)12

Co-reporter:Dafa Chen;Shansheng Xu;Haibin Song

European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 11) pp:1854-1864

Publication Date(Web):

DOI:10.1002/ejic.200701186

Abstract

Reactions of the pyridyl side chain functionalized indenes 3-R-C₉H₇ [R = (C₅H₄N)CH₂CMe₂ (1), (MeC₅H₃N)CH₂CMe₂ (2), (C₅H₄N)CH₂ (6)] with Ru₃(CO)₁₂ in refluxing xylene gave the facial coordinated indenyl cluster [μ₃-η⁵:η²:η²-(C₅H₃N)CH₂Me₂C(C₉H₆)]Ru₄(μ₃-CO)(CO)₇ (8), the syn-η⁵:η⁶-coordinated indenyl cluster [μ-η⁵:η⁶-(MeC₅H₃N)CH₂CMe₂(C₉H₆)Ru₂(CO)₃]₂ (10), and the η¹:η²-coordinated indenyl complex[η²-(C₅H₃N)CH₂(C₉H₇)][η¹:η²-(C₅H₄N)CH₂(C₉H₆)]Ru₂(CO)₄(18), respectively, in addition to the normal diruthenium complexes [(η⁵-RC₉H₆)Ru(CO)]₂(μ-CO)₂ [R = (C₅H₄N)CH₂CMe₂ (7), (MeC₅H₃N)CH₂CMe₂ (9), (C₅H₄N)CH₂ (17)]. When the pyridyl side chains were replaced by other bulky groups [R = tBu (3), PhCH₂Me₂C (4), (C₉H₆N)CH₂Me₂C (5)], the similar syn-η⁵:η⁶-coordinated indenyl clusters 12, 14, and 16 were also obtained. When 1 or 2 were treated with Ru₃(CO)₁₂ in refluxing heptane, the ionic clusters {[(C₅H₄N)CH₂Me₂C(C₉H₆)]Ru(CO)₂}⁺[HRu₆(CO)₁₈]^– (19), [(C₅H₄N)CH₂Me₂C(C₉H₈)]⁺[HRu₆(CO)₁₈]^– (20), and complex 8 or ionic clusters {[(MeC₅H₃N)CH₂Me₂C(C₉H₆)]Ru(CO)₂}⁺[HRu₆(CO)₁₈]^– (21) and [(MeC₅H₃N)CH₂Me₂C(C₉H₈)]⁺[HRu₆(CO)₁₈]^– (22) were obtained. Similar treatment of 5 or 6 with Ru₃(CO)₁₂ in refluxing heptane gave the ionic clusters [(C₉H₆N)CH₂Me₂C(C₉H₈)]⁺[HRu₆(CO)₁₈]^– (23) or {[η³-(C₅H₄N)CH(C₉H₇)][η²-(C₅H₄N)CH₂(C₉H₇)]Ru(CO)}⁺[HRu₆(CO)₁₈]^– (24), respectively, in addition to complex 18 in the latter case. The molecular structures of 8, 9, 10, 14, 17, 18, 21, 22, and 24 were determined by X-ray diffraction analysis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Reactions of the Doubly Bridged Bis(cyclopentadienyl) Dinuclear Molybdenum Complex (Me2C)(Me2Si)[(5-C5H3)Mo(CO)3]2 with a Carboxylate-Substituted Allene

Co-reporter:Bin Li;Congying Zhang;Shansheng Xu;Haibin Song

European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 8) pp:1277-1286

Publication Date(Web):

DOI:10.1002/ejic.200701030

Abstract

Reaction of the doubly bridged bis(cyclopentadienyl) dinuclear molybdenum complex (Me₂C)(Me₂Si)[(η⁵-C₅H₃)Mo(CO)₃]₂ (1) with equivalent molar amount of allene H₂C=C=CHCO₂Me in refluxing toluene gave four products: complex (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄(μ-η²-η²-HC≡CCH₂CO₂Me)] (3) (10 %) with a crosswise substituted alkyne bridge, η²-η²-HC≡CCH₂CO₂Me derived from a 1,3-hydrogen shift of H₂C=C=CHCO₂Me, complex (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₂(O)₂{μ-η¹-η³-C(CO₂Me)CHCH₂}] (6) (16 %) with a bridging η¹,η³-C(CO₂Me)CHCH₂ allylic group, and allene C–C coupled complexes (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄{μ-η³-η³-{MeO₂CCH(CH₂)C}(CHCHCHCO₂Me)}](4) (7 %) and (Me₂C)(Me₂Si)[(η⁵-C₅H₃)₂Mo₂(CO)₄{μ-η³-η³-{MeO₂CCH(CH₂)C}₂}] (5) (13 %), in which the two allene molecules were coupled in head-to-center and center-to-center coupling modes, respectively. When 1 was treated with an excess amount of H₂C=C=CHCO₂Me, only C–C coupled products 4 (10 %) and 5 (22 %) were obtained. In comparison, reaction of the singly bridged bis(cyclopentadienyl) dinuclear molybdenum complex (Me₂C)[(η⁵-C₅H₄)Mo(CO)₃]₂ (2) with H₂C=C=CHCO₂Me only gave the η²-η² coordinated complex (Me₂C)[(η⁵-C₅H₄)Mo₂(CO)₄(μ-η²-η²-H₂CCCHCO₂Me)] (7) (21 %). These results marked the different reactivities of doubly bridged bis(cyclopentadienyl) dinuclear molybdenum complex 1 and the corresponding singly bridged analogue 2. The formation of these complexes was discussed and the molecular structures of 3–7 were determined by X-ray diffraction. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Synthesis and structures of aryl-substituted tetramethylcyclopentadienyl dinuclear metal carbonyl complexes

Co-reporter:Jin Lin, Peng Gao, Bin Li, Shansheng Xu, Haibin Song, Baiquan Wang

Inorganica Chimica Acta 2006 Volume 359(Issue 14) pp:4503-4510

Publication Date(Web):1 November 2006

DOI:10.1016/j.ica.2006.05.043

A series of 14 aryl-substituted tetramethylcyclopentadienyl dinuclear metal carbonyl complexes have been synthesized by treating the corresponding ligands (C5Me4C6H4X-4) (X = H, Me, Cl, OMe) with Ru3(CO)12, Fe(CO)5, or Mo(CO)3(MeCN)3, respectively in refluxing xylene. It showed that the electronic effects of the substituents had influence on the molecular structures and reactions of the complexes, especially for the ruthenium and molybdenum complexes. In the reactions of aryl-substituted tetramethylcyclopentadiene with Mo(CO)3(MeCN)3, the electron-withdrawing effect of the substituent in the para position of benzene ring is favorable to produce the Mo–Mo triple bonded complexes, but the electron-donor effect of the substituent in the para position of benzene ring is favorable to produce the Mo–Mo single bonded complexes. In a given condition, the Mo–Mo single bonded complex could be transformed into the corresponding Mo–Mo triple bonded complex. The structures of nine complexes were determined by single crystal X-ray diffraction.A series of 14 aryl-substituted tetramethylcyclopentadienyl dinuclear metal carbonyl complexes have been synthesized by treating the corresponding ligands (C5Me4C6H4X-4) (X = H, Me, Cl, OMe) with Ru3(CO)12, Fe(CO)5, or Mo(CO)3(MeCN)3 in refluxing xylene, respectively.

Synthesis and structures of cycloalkylidene-bridged mixed cyclopentadienyl-indenyl tetracarbonyl diruthenium complexes

Co-reporter:Jin Lin;Shuang Luo;Bin Cheng;Shansheng Xu;Haibin Song

Applied Organometallic Chemistry 2006 Volume 20(Issue 6) pp:

Publication Date(Web):23 MAY 2006

DOI:10.1002/aoc.1067

A series of cycloalkylidene-bridged mixed cyclopentadienyl-indenyl tetracarbonyl diruthenium complexes (η⁵:η⁵-RC₅H₃CR′₂C₉H₆)Ru₂(CO)₂(µ-CO)₂ [R = H, R′, R′ = Me₂ (1), (CH₂)₄ (2), (CH₂)₅ (3), (CH₂)₆ (4); R = ^tBu, R′, R′ = Me₂ (5), (CH₂)₄ (6), (CH₂)₅ (7)] have been synthesized by reactions of the corresponding ligands RC₅H₄CR′₂C₉H₇ with Ru₃(CO)₁₂ in refluxing xylene. The molecular structures of 2, 6 and 7 have been determined by X-ray diffraction. Copyright © 2006 John Wiley & Sons, Ltd.

Synthesis and structures of dinuclear iron, molybdenum and tungsten complexes derived from (PhCHCHPh)-coupled bis(cyclopentadiene)

Co-reporter:Bin Li, Baiquan Wang, Shansheng Xu, Xiuzhong Zhou

Journal of Organometallic Chemistry 2005 Volume 690(Issue 23) pp:5309-5317

Publication Date(Web):15 November 2005

DOI:10.1016/j.jorganchem.2005.05.004

Reductive coupling of phenylfulvene with amalgamated calcium metal followed by hydrolysis yields CpPhCHCHPhCp (1) in high yield. Refluxing ligand 1 and Fe(CO)5 in xylene produces (PhCHCHPh)-coupled bis(cyclopentadienyl) tetracarbonyl diiron (PhCHCHPh)[(η5-C5H4)Fe(CO)2]2 (2) as a mixture of meso (2-meso) and racemic isomers (2-rac). The pure racemic isomers of the Mo and W analogues (3-rac and 4-rac) have been synthesized by lithiation of ligand 1 and addition of (MeCN)3M(CO)3 (M = Mo, W) followed by oxidation with 2 equiv. of ferrocenium tetrafluoroborate. All the new complexes have been fully characterized. The molecular structures of 1-meso, 2-meso, 2-rac, 3-rac, and 4-rac have been determined by X-ray diffraction analysis.Reaction of ligand CpPhCHCHPhCp (1) with Fe(CO)5 in refluxing xylene, or the lithium salts of 1 with (MeCN)3M(CO)3 (M = Mo, W) followed by oxidation, afforded (PhCHCHPh)-coupled bis(cyclopentadienyl) dinuclear iron, molybdenum and tungsten complexes.

Synthesis and Structures of Cycloalkylidene-Bridged Cyclopentadienyl Metallocene Catalysts: Effects of the Bridges of Ansa-Metallocene Complexes on the Catalytic Activity for Ethylene Polymerization

Co-reporter:Baiquan Wang ;Bin Mu;Xiaobin Deng;Huiling Cui;Shansheng Xu ;Xiuzhong Zhou ;Fenglou Zou;Yang Li Dr.;Ling Yang;Yufei Li ;Youliang Hu

Chemistry - A European Journal 2005 Volume 11(Issue 2) pp:

Publication Date(Web):2 DEC 2004

DOI:10.1002/chem.200400750

A series of cycloalkylidene-bridged cyclopentadienyl metallocene complexes, [(CH₂)_nC(C₅H₄)₂MCl₂] (M = Ti, n = 4 (4), 5 (5), 6 (6); M = Zr, n = 4 (7), 5 (8), 6 (9); M = Hf, n = 4 (10), 5 (11), 6 (12)), have been synthesized and applied to ethylene polymerization after activation with methyl aluminoxane (MAO). The cycloalkylidene-bridged titanocene catalysts exhibit much higher activities than the corresponding zirconocene and hafnocene analogues, and have the highest activities at higher temperatures. In comparison, the silacyclopentylidene-bridged metallocene complexes [(CH₂)₄Si(C₅H₄)₂MCl₂] (M = Ti (13), Zr (14)) and isopropylene-bridged metallocene complexes [Me₂C(C₅H₄)₂MCl₂] (M = Ti (15), Zr (16)) have also been synthesized and applied to ethylene polymerization. In both cases, the titanocene complexes show much higher activities than the corresponding zirconocene analogues, especially at a lower temperature. The molecular structures of complexes 4–9 have been determined by X-ray diffraction. The structure–activity relationships, especially the effects of the bridges of ansa-metallocene complexes, are discussed.

Synthesis and Thermal Rearrangement of Tetramethyldisilane-bridged Bis(cyclopentadienyl) Diiron Complexes with Bis (phosphine) Substitution

Co-reporter:Sun Xiu-Li;Wang Bai-Quan;Xu Shan-Sheng;Zhou Xiu-Zhong

Chinese Journal of Chemistry 2003 Volume 21(Issue 3) pp:332-335

Publication Date(Web):26 AUG 2010

DOI:10.1002/cjoc.20030210322

Photolysis of (Me₂SiSiMe₂) [C₅H₄Fe (CO)₂]₂ with a series of bis-(phosphine) ligands Ph₂P(CH₂)_n PPh₂ (n = 1–4) leads to the formation of the corresponding diiron complexes with intramolecular and intermolecular bis (phosphine) substitution. When these complexes were heated in refluxing xylene, only in the complexes with intermolecular bis (phosphine) substitution the thermal rearrangement reaction occurred.

Synthesis and Structure of a Novel Cluster with Trigonal-bipyramidal Ge2Ru3 Core

Co-reporter:Yong-Qiang Zhang;Bai-Quan Wang;Shan-Sheng Xu;Xiu-Zhong Zhou

Chinese Journal of Chemistry 2002 Volume 20(Issue 11) pp:

Publication Date(Web):26 AUG 2010

DOI:10.1002/cjoc.20020201139

When t-BuC₅H₄Me₂GeGeMe₂C₅E₄Bu-t and Ru₃ (CO)₁₂ were refluxed in nonane, a novel germanium-ruthenium duster with a trigonal-bipyramidal Ge₂Ru₃ core {(μ³-Ge) [Ru(CO)₂ (η⁵-C₅H₄Bu-t)]}₂Ru₃ (CO)₉ (1) and a dinuclear ruthenium complex [(Me₂Ge)(η⁵-C₅H₃Bu-t)Ru₂(CO)₆] (2) were obtained. The structures of 1 and 2 were fully characterized by ¹H NMR, ¹³C NMR, IR spectra and elemental analysis, and 1 has also been determined by X-ray diffraction analysis.

Rhodium-catalyzed C2 and C4 C–H activation/annulation of 3-(1H-indol-3-yl)-3-oxopropanenitriles with internal alkynes: a facile access to substituted and fused carbazoles

Co-reporter:Tao Zhou, Bin Li and Baiquan Wang

Chemical Communications 2017 - vol. 53(Issue 47) pp:NaN6346-6346

Publication Date(Web):2017/05/18

DOI:10.1039/C7CC02808C

Rhodium-catalyzed C–H activation of 3-(indolin-1-yl)-3-oxopropanenitriles with diazo compounds and tandem cyclization leading to hydrogenated azepino[3,2,1-hi]indoles

Co-reporter:Tao Zhou, Bin Li and Baiquan Wang

Chemical Communications 2016 - vol. 52(Issue 98) pp:NaN14120-14120

Publication Date(Web):2016/11/10

DOI:10.1039/C6CC07758G

Rh(III)-Catalyzed C–H activation of 3-(indolin-1-yl)-3-oxopropanenitriles with diazo compounds and cyclization leading to seven-membered ring scaffolds has been developed. These reactions involving tandem C–H activation, cyclization, and condensation steps proceed efficiently and display a broad scope of substrates.

Ru(II)-catalyzed amidation reactions of 8-methylquinolines with azides via C(sp3)–H activation

Co-reporter:Bingxian Liu, Bin Li and Baiquan Wang

Chemical Communications 2015 - vol. 51(Issue 91) pp:NaN16337-16337

Publication Date(Web):2015/09/10

DOI:10.1039/C5CC06230F

Regioselective synthesis of multisubstituted isoquinolones and pyridones via Rh(III)-catalyzed annulation reactions

Co-reporter:Liangliang Shi, Ke Yu and Baiquan Wang

Chemical Communications 2015 - vol. 51(Issue 97) pp:NaN17280-17280

Publication Date(Web):2015/10/06

DOI:10.1039/C5CC05977A

Rh(III)-catalyzed synthesis of 1-aminoindole derivatives from 2-acetyl-1-arylhydrazines and diazo compounds in water

Co-reporter:Yujie Liang, Ke Yu, Bin Li, Shansheng Xu, Haibin Song and Baiquan Wang