Mei-Ming Luo

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Name: 罗美明; Luo, MeiMing

Organization: Sichuan University , China

Department: College of Chemistry

Title: Professor(PhD)

TOPICS

Polymer

POSS

Chemicals
References

Iron-catalyzed synthesis of benzoxazoles by oxidative coupling/cyclization of phenol derivatives with benzoyl aldehyde oximes

Co-reporter:Sen Gao;Liming Gao;Hong Meng;Meiming Luo;Xiaoming Zeng

Chemical Communications 2017 vol. 53(Issue 71) pp:9886-9889

Publication Date(Web):2017/08/31

DOI:10.1039/C7CC04965J

An iron-catalyzed oxidative coupling/cyclization reaction for the synthesis of benzoxazoles at room temperature is reported. This reaction was enabled by an inexpensive iron(III) catalyst by treating readily available phenol derivatives with benzoyl aldehyde oximes. Mechanistic studies show that benzoyl aldehyde oxime is not only used as a substrate, but also serves as an ancillary ligand to support the iron salt in the promotion of the transformation.

Iron-catalyzed synthesis of arylsulfinates through radical coupling reaction

Co-reporter:Weixi Zhang and Meiming Luo

Chemical Communications 2016 vol. 52(Issue 14) pp:2980-2983

Publication Date(Web):11 Jan 2016

DOI:10.1039/C5CC09830K

A novel strategy for installation of a sulfonyl fragment into arenes has been accomplished via an iron-catalyzed radical coupling reaction. Arene radicals derived from diaryliodoniums via single electron transfer reaction combine with sulfoxylate anion radicals readily generated from commercially available rongalite (HOCH2SO2Na·2H2O) to afford arylsulfinates efficiently at room temperature. In this protocol, a broad range of functional groups are tolerated to give products in good yields.

Catalytic Synthesis of 3-Thioindoles Using Bunte Salts as Sulfur Sources under Metal-Free Conditions

Co-reporter:Hong Qi, Tongxin Zhang, Kefeng Wan, and Meiming Luo

The Journal of Organic Chemistry 2016 Volume 81(Issue 10) pp:4262-4268

Publication Date(Web):April 27, 2016

DOI:10.1021/acs.joc.6b00636

An efficient catalytic method for the synthesis of 3-thioindoles has been successfully developed, which uses odorless, stable, readily available crystalline Bunte salts as the sulfenylating agents, iodine as nonmetallic catalyst, and DMSO as both the oxidant and solvent. This method is practical and environmentally benign in terms of sulfur sources, catalyst, and solvent. The catalytic reaction is selective at the C3 position of indoles and compatible with a wide range of substrates, giving the desired products in good to excellent yields.

Synthesis and catalytic activity of nickel(II) complexes of CNC pincer-type N-heterocyclic carbene ligands

Co-reporter:Shuchao Wang, Fang Ren, Yuping Qiu, Meiming Luo

Journal of Organometallic Chemistry 2015 Volume 788() pp:27-32

Publication Date(Web):15 July 2015

DOI:10.1016/j.jorganchem.2015.04.019

•A new type of nickel(II) complexes containing CNC pincer-type bis-NHC ligands was synthesized.•One of the complexes was characterized by X-ray diffraction.•The complexes showed high efficiency in catalyzing Suzuki cross-coupling reactions.Air- and moisture-stable nickel(II) complexes 2a–c of CNC pincer-type N-heterocyclic carbene ligands have been prepared from the corresponding imidazolium salts by carbene–transfer reaction of a silver-NHC complex with Ni(DME)Cl2 (DME = dimethoxylethane). Pincer complexes 2a–c are characterized by mass and NMR spectroscopy. The structure of 2a is also identified by X-ray diffraction analysis. Pincer complex 2a has been shown to be active catalyst for the Suzuki coupling reactions.A new type of nickel(II) complexes containing CNC pincer-type bis-NHC ligands with an anionic diarylamindo backbone has been synthesized and characterized.

Iron-Catalyzed N-Arylsulfonamide Formation through Directly Using Nitroarenes as Nitrogen Sources

Co-reporter:Weixi Zhang, Junyao Xie, Bin Rao, and Meiming Luo

The Journal of Organic Chemistry 2015 Volume 80(Issue 7) pp:3504-3511

Publication Date(Web):March 5, 2015

DOI:10.1021/acs.joc.5b00130

One-step, catalytic synthesis of N-arylsulfonamides via the construction of N–S bonds from the direct coupling of sodium arylsulfinates with nitroarenes was realized in the presence of FeCl2 and NaHSO3 under mild conditions. In this process, stable and readily available nitroarenes were used as nitrogen sources, and NaHSO3 acted as a reductant to provide N-arylsulfonamides in good to excellent yields. A broad range of functional groups were very well-tolerated in this reaction system. In addition, mechanistic studies indicated that the N–S bond might be generated through direct coupling of nitroarene with sodium arylsulfinate prior to the reduction of nitroarenes by NaHSO3. Accordingly, a reaction mechanism involving N-aryl-N-arenesulfonylhydroxylamine as an intermediate was proposed.

POSS-based hybrid porous materials with exceptional hydrogen uptake at low pressure

Co-reporter:Zhijun Wei, Xuan Luo, Lin Zhang, Meiming Luo

Microporous and Mesoporous Materials 2014 Volume 193() pp:35-39

Publication Date(Web):15 July 2014

DOI:10.1016/j.micromeso.2014.03.010

•The choice of reactant concentration affects the porous properties of the obtained hybrid porous materials.•The BET specific surface area is up to 1080 m2 g−1.•The hydrogen uptake can reach to 2.00 wt.% at 1.0 bar and 77 K.Hybrid porous materials based on AIBN initiated radical polymerization of octavinylsilsesquioxane in THF were reported in detail. The choice of reactant concentration has a major influence on their porous properties. The resulting hybrid porous materials exhibit high BET specific surface areas (up to 1080 m2 g−1) and exceptional hydrogen uptake (2.00 wt.% at 1.0 bar and 77 K).Graphical abstract

Metal-free reduction of tertiary phosphine oxides with Hantzsch ester

Co-reporter:Tong-Xin Zhang, Wei-Xi Zhang, Mei-Ming Luo

Chinese Chemical Letters 2014 Volume 25(Issue 1) pp:176-178

Publication Date(Web):January 2014

DOI:10.1016/j.cclet.2013.09.007

The (COCl)2/Hantzsch ester is found to be an effective system for the metal-free reduction of tertiary phosphine oxides. The reaction proceeds under mild conditions, and is applicable to triarylphosphine oxides and alkyldiarylphosphine oxides to produce the corresponding tertiary phosphines in good to excellent yields. This new finding provides a practical, convenient and metal-free method for the reduction of tertiary phosphine oxides to tertiary phosphines, and shows potential application in organic synthesis.The (COCl)2/Hantzsch ester is found to be an effective system for the metal-free reduction of tertiary phosphine oxides. The reaction proceeds under mild conditions, and is applicable to triarylphosphine oxides and alkyldiarylphosphine oxides to produce the corresponding tertiary phosphines in good to excellent yields.

Au(I)–N-heterocyclic carbene complex-catalyzed synthesis of 1-substituted benzo[b][1,4]diazepines from N-substituted o-phenylenediamines and terminal alkynes

Co-reporter:Pei Guo, Xiaoming Zeng, Si Chen, Meiming Luo

Journal of Organometallic Chemistry 2014 Volume 751() pp:438-442

Publication Date(Web):1 February 2014

DOI:10.1016/j.jorganchem.2013.06.026

•An Au(I)-NHC-catalyzed process for benzo[b][1,4]diazepines was developed.•1-Substituted benzo[b][1,4]diazepines were efficiently prepared.•Fused tricyclic benzo[b][1,4]diazepines were accessed for the first time.1-Substituted benzo[b][1,4]diazepines which are difficult to synthesize by traditional methods have been prepared by an Au(I)–N-heterocyclic carbene complex-catalyzed tandem hydroamination/cyclization process. This protocol features the one-pot formation of a seven-membered N-heterocycle via atom-economic hydroamination/cyclization reactions of readily available N-substituted o-phenylenediamines and terminal alkynes. Based on this strategy, fused tricyclic benzo[b][1,4]diazepines have been accessed for the first time.1-Substituted and fused polycyclic benzo[b][1,4]diazepines which are difficult to be accessed previously have been synthesized by Au(I)–NHC complex-catalyzed tandem hydroamination/cyclization protocol.

Synthesis and thermal polymerization of perylene bisimide containing benzocyclobutene groups

Co-reporter:Zhi-Jun Wei, Ye-Wei Xu, Lin Zhang, Mei-Ming Luo

Chinese Chemical Letters 2014 Volume 25(Issue 10) pp:1367-1370

Publication Date(Web):October 2014

DOI:10.1016/j.cclet.2014.04.022

Fourfold benzocyclobutene-functionalized perylene bisimide (PBI 4) has been synthesized and its structure was characterized by FTIR, MS and NMR. PBI 4 can react either with itself, or the appropriate dienophiles to form the corresponding products under appropriate temperature. The polymer film obtained from the reaction of PBI 4 with methyl vinyl silicone rubber possessed excellent film forming properties including flatness. The optical properties of PBI 4 and polymer film obtained from the reaction of PBI 4 and methyl vinyl silicone rubber have been determined by UV/vis and fluorescence spectroscopy.Fourfold benzocyclobutene-functionalized perylene bisimide has been synthesized and its thermal polymerization and optical properties have been investigated.

A Convenient and General Reduction of Amides to Amines with Low-Valent Titanium

Co-reporter:Tongxin Zhang;Yan Zhang;Weixi Zhang ;Meiming Luo

Advanced Synthesis & Catalysis 2013 Volume 355( Issue 14-15) pp:2775-2780

Publication Date(Web):

DOI:10.1002/adsc.201300355

New cyclen derivative ligand for thorium(IV) separation by solvent extraction

Co-reporter:Qiao Deng;Yongdong Jin;Qinggui Wang

Journal of Radioanalytical and Nuclear Chemistry 2013 Volume 295( Issue 1) pp:125-133

Publication Date(Web):2013 January

DOI:10.1007/s10967-012-1879-7

A new N-containing ligand, 1,4,7,10-tetra-(4-nitrobenzyl)-1,4,7,10-tetraazacyclo-dodecane (L), was synthesized, and its structure was determined by 1H NMR, high resolution mass spectrometry and X-ray diffraction. L crystallized in the monoclinic system (P21/n space group; a = 7.7895(2) Å, b = 22.9592(5) Å, c = 9.9204(2) Å; α = 90.00°, β = 105.481(3)°, γ = 90.00°; Z = 2). Slope analysis and the continuous variation method demonstrated that 1:2 complexes between Th(IV) and L are formed; furthermore, the XPS analysis suggested that two oxygen atoms might be provided by two water molecules and that eight nitrogen atoms might be provided by two L molecules to form a ten-coordinate compound with Th(IV). The extraction equilibrium constant for the complex formation between Th(IV) and L was logKex = 6.95 ± 0.15 (25 °C), and the Gibbs free energy, ΔGo (25 °C), of the 1:2 Th–L complex in dichloromethane was −39.56 kJ/mol. The L ligand in dichloromethane only slightly extracted Th(IV) from HNO3 solution at pH = 1–3; however, an extraction efficiency of E = 94.9 ± 0.3 % was observed at pH = 4.63. The selectivity of L for the Th(IV) cation over other cations (i.e., Cs(I), Sr(II), Y(III), La(III), Sm(III), Eu(III), U(VI), and 241Am(III)) was evaluated. Furthermore, the stripping experiments showed that the stripping agent (0.5 mol/L Na2CO3 + 0.1 mol/L EDTA) could provide an optimal condition for stripping thorium, and thorium recovery was up to 91.6 ± 0.1 %.

Catalytic desulfitative homocoupling of sodium arylsulfinates in water using PdCl2 as the recyclable catalyst and O2 as the terminal oxidant

Co-reporter:Bin Rao, Weixi Zhang, Lan Hu and Meiming Luo

Green Chemistry 2012 vol. 14(Issue 12) pp:3436-3440

Publication Date(Web):18 Oct 2012

DOI:10.1039/C2GC36550B

A green and convenient approach to symmetrical biaryls has been developed. The catalytic desulfitative homocoupling of various inexpensive and readily available sodium arylsulfinates in environment-friendly solvent, water, and under clean oxidant, molecular O2, afforded symmetrical biaryls in good yields. What's more, water can hold the noble catalyst PdCl2 for recycling several times easily, and facilitate separating insoluble organic product.

Acyclic Palladium(II)-N-heterocyclic Carbene Metallacrown Ether Complexes: Synthesis, Structure and Catalytic Activity

Co-reporter:Weixi Zhang;Xiaoqin Zhang;Meiming Luo

Chinese Journal of Chemistry 2012 Volume 30( Issue 7) pp:1423-1428

Publication Date(Web):

DOI:10.1002/cjoc.201100596

Abstract

Novel acyclic Pd(II)-N-heterocyclic carbene (NHC) metallacrown ethers 5a, 5b have been synthesized. Reaction of the imidazolium salts bearing a long polyether chain with Ag₂O afforded Ag-NHC complexes, which then reacted as carbene transfer agent with PdCl₂(MeCN)₂ to give the desired acyclic Pd(II)-NHC metallacrown ether complexes 5a and 5b. The ¹H NMR and ¹³C NMR spectra show 5a and 5b exist as mixtures of cis and trans isomers in solution. The trans isomer of 5a was characterized by X-ray diffraction, which clearly demonstrated two pseudo-crown ether cavities in trans-5a. Pd(II)-NHC complexes 5a and 5b have been shown to be highly effective in the Suzuki-Miyaura reactions of a variety of aryl bromides in neat water without the need of inert gas protection.

Group IV M-POSS (M=Zr, Hf) Coordination Polymers

Co-reporter:Zhijun Wei;Hongbo Ren;Lin Zhang;Meiming Luo

Chinese Journal of Chemistry 2012 Volume 30( Issue 10) pp:2591-2594

Publication Date(Web):

DOI:10.1002/cjoc.201200696

Abstract

The synthesis and characterization of Zr-POSS and Hf-POSS coordination polymers were reported. The IR data and the solid-state ²⁹Si MAS NMR indicated the existence of SiOM linkage. The polarized optical microscopy images and the XRD data suggested their crystalline nature.

Reduction of hydrazines to amines with aqueous solution of titanium(III) trichloride

Co-reporter:Yan Zhang, Qiang Tang and Meiming Luo

Organic & Biomolecular Chemistry 2011 vol. 9(Issue 13) pp:4977-4982

Publication Date(Web):13 Apr 2011

DOI:10.1039/C1OB05328K

N–N bond cleavage in hydrazines is widely used in the preparation of amines and thus occupies a significant place in organic synthesis. In this paper, we report a new method for the reductive cleavage of N–N bonds in hydrazines by commercially available and cheap aqueous titanium(III) trichloride. The reaction proceeds smoothly under a broad pH range from acidic to neutral and basic conditions to afford amines in good yields. This method is compatible with substrates containing functionalities such as C–C double bonds, benzyl–nitrogen bonds, benzyloxy and acyl groups.

Preparation of POSS-based organic–inorganic hybrid mesoporous materials networks through Schiff base chemistry

Co-reporter:Yuancheng Qin, Hongbo Ren, Fanghua Zhu, Lin Zhang, Chengwei Shang, Zhijun Wei, Meiming Luo

European Polymer Journal 2011 Volume 47(Issue 5) pp:853-860

Publication Date(Web):May 2011

DOI:10.1016/j.eurpolymj.2011.02.024

The synthesis of novel POSS-based organic–inorganic hybrid mesoporous materials networks functionalized with amine groups through Schiff base chemistry is reported. The material shows uniform mesoporous size. Nitrogen sorption analyses give high specific surface areas of 641–1103 m2 g−1 with pore volumes of 0.47–0.53 mL g−1. The combined results of FTIR, solid 13C NMR and 29Si NMR show that the POSS building blocks are successfully weaved in the porous structure without obvious alteration of the POSS structural characteristics. The hybrid materials show excellent thermal stability.

Homocoupling of Arylboronic Acids Catalyzed by CuCl in Air at Room Temperature

Co-reporter:Guanjun Cheng ;Meiming Luo

European Journal of Organic Chemistry 2011 Volume 2011( Issue 13) pp:2519-2523

Publication Date(Web):

DOI:10.1002/ejoc.201001729

Abstract

Homocoupling of arylboronic acids has been successfully carried out by using the inexpensive simple copper salt CuCl as the catalyst in methanol to obtain symmetric biaryls in good to excellent yields. The reaction proceeds with a CuCl loading of 2 mol-% under extremely mild conditions: in air, at room temperature, without the need of any additives such as base, oxidant, or ligand.

Poly(methyl methacrylate)/Methacryl-POSS Nanocomposites with Excellent Thermal Properties

Co-reporter:Yuancheng Qin;Yutie Bi;Hongbo Ren;Fanghua Zhu; Dr. Meiming Luo;Lin Zhang

Chinese Journal of Chemistry 2010 Volume 28( Issue 12) pp:2527-2532

Publication Date(Web):

DOI:10.1002/cjoc.201190033

Abstract

Poly(methyl methacrylate) (PMMA) nanocomposites containing (methacryloxy)propyl polyhedral oligomeric silsesquioxane (methacryl-POSS) were prepared by bulk-polymerization process. The structures of the products were characterized by FTIR, solid-state NMR, TEM, XRD, DSC, TGA, XPS and UV-Vis spectra. The hybrid materials were found to be largely homogeneous. DSC and TGA results indicate that the thermal properties of PMMA nanocomposites are significantly improved. The glass transition temperature (T_g) and thermal decomposition temperature (T_dec) of the nanocomposites increased by 58 and 110°C, respectively. The bulk hybrid material maintains excellent optical transparency in visible region.

Synthesis of a carbene transfer organometallic polymer and application to forming a recyclable heterogeneous catalyst for the Suzuki reactions of aryl chlorides

Co-reporter:Xiaoming Zeng, Tongxin Zhang, Yuancheng Qin, Zhijun Wei and Meiming Luo

Dalton Transactions 2009 (Issue 39) pp:8341-8348

Publication Date(Web):10 Aug 2009

DOI:10.1039/B904944B

An efficient and versatile synthetic approach to NHC-based organometallic polymers has been developed by a simple three-step synthesis. A novel brush polymer having imidazolium salt side chains (P2) was firstly synthesized through postpolymerization modification of P1, which permits access to Ag(I)–NHC-based side chain polymer (P3) at room temperature in high yield. P3 was applied as a carbene transfer agent to form a Pd–NHC-containing polymer (P4) by the transmetallation reaction of Ag(I)–NHCs in the side chains. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis indicated that 77% of Ag(I)–NHCs in the side chains of P3 were transmetallated. The resulting Pd–NHC-containing polymer (P4) showed high catalytic activity and reusability in the Suzuki reactions of aryl chlorides and aryl boronic acids. This novel Pd–NHC-containing polymeric catalyst was used five times and still remained active giving the desired biaryl products in 70% yield in the fifth run of the cross-coupling reaction of deactivated 4-chloroanisole with phenylboronic acid.

Synthesis of 1,1′-binaphthyl-2,2′-diamine from 2-naphthol under atmospheric pressure

Co-reporter:Qiang Feng, Chao Zhang, Qiang Tang, Mei Ming Luo

Chinese Chemical Letters 2009 Volume 20(Issue 10) pp:1150-1152

Publication Date(Web):October 2009

DOI:10.1016/j.cclet.2009.05.033

A practical protocol to obtain 1,1′-binaphthyl-2,2′-diamine was developed from 2-naphthol and 2-naphthylhydrazine under mild conditions: solvent-free, 125–130 °C, atmospheric pressure. The convenient procedure makes the process amenable for large-scale synthesis of the versatile compound.

Palladium(II)−N-Heterocyclic Carbene Metallacrown Ether Complexes: Synthesis, Structure, and Catalytic Activity in the Suzuki−Miyaura Reaction

Co-reporter:Xiaoqin Zhang, Yuping Qiu, Bin Rao and Meiming Luo

Organometallics 2009 Volume 28(Issue 10) pp:3093-3099

Publication Date(Web):April 22, 2009

DOI:10.1021/om8011695

Pd(II)−N-heterocyclic carbene (NHC) metallacrown ether complexes have been synthesized for the first time. Reaction of bis(imidazolium) salts with a long polyether chain with Ag2O afforded silver−NHC complexes [Ag2(L)Cl2] 5, which reacted as carbene transfer reagents with palladium salts to give Pd(II)−NHC metallacrown ether complexes 6a,b. The Ag(I)−NHC complex 5b possesses a one-dimensional chain configuration by each Ag(I) center coordinated to one carbene and two bridging chlorides. Each of Pd(II)−NHC metallacrown ether complexes 6a,b contains a 25-membered macrocyclic NHC metallacrown ether formed by a bidentate chelate bis(carbene) ligand with a long flexible linkage and a Pd(II). The coordination geometry on the Pd(II) is approximately square planar. Pd(II)−NHC metallacrown ether complexes 6a and 6b have been shown to be highly effective in the Suzuki−Miyaura reactions of a variety of aryl bromides in neat water without the need of inert gas protection.

Synthesis, Structure, and Catalytic Activity of Palladium(II) Complexes of New CNC Pincer-Type N-Heterocyclic Carbene Ligands

Co-reporter:Wei Wei, Yuancheng Qin, Meiming Luo, Pingfang Xia and Man Shing Wong

Organometallics 2008 Volume 27(Issue 10) pp:2268-2272

Publication Date(Web):April 12, 2008

DOI:10.1021/om800007s

New CNC pincer-type N-heterocyclic carbene ligands with a central diarylamido moiety are presented. Palladium(II) pincer complexes of type [Pd(L)Cl] (L = bis[2-(3-alkylimidazolin-2-yliden-1-yl)-4-methylphenyl]amido) 5a−c (5a, alkyl = benzyl; 5b, alkyl = n-butyl; 5c, alkyl = 2,4,6-trimethylbenzyl) were obtained from the corresponding silver carbene complexes and [PdCl2(MeCN)2] without addition of external bases. The palladium pincer complex 5a was characterized by X-ray diffraction. The molecular structure of 5a shows a distorted square-planar coordination geometry for the palladium atom. Pincer complexes 5a−c have been shown to be active catalysts for the Suzuki−Miyaura reactions.

Iron-catalyzed synthesis of arylsulfinates through radical coupling reaction

Co-reporter:Weixi Zhang and Meiming Luo

Chemical Communications 2016 - vol. 52(Issue 14) pp:NaN2983-2983

Publication Date(Web):2016/01/11

DOI:10.1039/C5CC09830K

Reduction of hydrazines to amines with aqueous solution of titanium(III) trichloride

Co-reporter:Yan Zhang, Qiang Tang and Meiming Luo

Organic & Biomolecular Chemistry 2011 - vol. 9(Issue 13) pp:NaN4982-4982

Publication Date(Web):2011/04/13

DOI:10.1039/C1OB05328K

Synthesis of a carbene transfer organometallic polymer and application to forming a recyclable heterogeneous catalyst for the Suzuki reactions of aryl chlorides

Co-reporter:Xiaoming Zeng, Tongxin Zhang, Yuancheng Qin, Zhijun Wei and Meiming Luo