Co-reporter:Xiangjian Meng and Sunggak Kim
Organic Letters 2013 Volume 15(Issue 8) pp:1910-1913
Publication Date(Web):April 1, 2013
DOI:10.1021/ol400565r
The new monophosphonic acid directing group is successfully utilized in the Pd(II)-catalyzed ortho-olefination of benzylic phosphonic monoesters and offers further development of other phosphoryl-related directing groups in the transition-metal-catalyzed C–H activations.
Co-reporter:Li Yan Chan, Sunggak Kim, Taekyu Ryu and Phil Ho Lee
Chemical Communications 2013 vol. 49(Issue 41) pp:4682-4684
Publication Date(Web):11 Apr 2013
DOI:10.1039/C3CC41107A
A highly efficient Pd-catalyzed ortho-alkenylation is reported using a mono-phosphoric acid-directing group for the first time. This phosphoric acid-directing group is successfully utilized for the synthesis of various alkenylated products and offers a new approach to transition-metal-catalyzed C–H activation.
Co-reporter:Li Yan Chan, Lilian Cheong, and Sunggak Kim
Organic Letters 2013 Volume 15(Issue 9) pp:2186-2189
Publication Date(Web):April 19, 2013
DOI:10.1021/ol400732q
Functionalized biaryl compounds were successfully synthesized using phosphates as the ortho-directing group in the Pd(II)/Pd(IV) catalytic cycle.
Co-reporter:Bathoju Chandra Chary, Sunggak Kim, Youngchul Park, Jinsik Kim, and Phil Ho Lee
Organic Letters 2013 Volume 15(Issue 11) pp:2692-2695
Publication Date(Web):May 17, 2013
DOI:10.1021/ol4009987
This communication describes the first phosphoramidate directing group for synthetically useful arylation. Remarkably, the nature of a new directing group drives selective C–H bond activation to afford diverse N-aryl phosphoramidates in good to excellent yields at room temperature.
Co-reporter:Kelvin Kau Kiat Goh, Sunggak Kim, and Samir Z. Zard
Organic Letters 2013 Volume 15(Issue 18) pp:4818-4821
Publication Date(Web):September 6, 2013
DOI:10.1021/ol402213k
A free-radical approach for the synthesis of functionalized 1,5-diketones has been accomplished through an effective combination play between alkenylacylphosphonates and keto-xanthates as radical surrogates of enolates and enones, respectively.
Co-reporter:Bathoju Chandra Chary and Sunggak Kim
Organic & Biomolecular Chemistry 2013 vol. 11(Issue 40) pp:6879-6882
Publication Date(Web):20 Aug 2013
DOI:10.1039/C3OB41548A
Rhodium(III)-catalyzed C–H olefination of aryl phosphonic esters is reported for the first time. In this mild and efficient process, the phosphonic ester group is utilized successfully as a new directing group. In addition, mono-olefination for aryl phosphonates is observed using a phosphonic diamide directing group.
Co-reporter:Dahan Eom;Juntae Mo;Phil Ho Lee;Zhiming Gao
European Journal of Organic Chemistry 2013 Volume 2013( Issue 3) pp:533-540
Publication Date(Web):
DOI:10.1002/ejoc.201201270
Abstract
A synthetic method was developed for the preparation of vinyl sulfides and vinylamines from arylalkynyl phenyl sulfides and sulfonamides. Under mild conditions, a catalytic intramolecular hydroarylation reaction was carried out in the presence of FeCl3 and AgOTf (OTf = trifluoromethanesulfonate) in 1,2-dichloroethane. A variety of 1,2-dihydronaphthalenes, 2H-chromenes, and 1,2-dihydroquinolines containing a phenylsulfenyl or N-phenyl-N-tosyl group on the sp2-hybridized benzylic carbon were prepared in good to excellent yields. The present method could be extended to the preparation of dihydropyrano[2,3-g]chromenes through a twofold Fe-catalyzed hydroarylation by a selective 6-endo mode.
Co-reporter:Xiangjian Meng and Sunggak Kim
The Journal of Organic Chemistry 2013 Volume 78(Issue 22) pp:11247-11254
Publication Date(Web):October 4, 2013
DOI:10.1021/jo401716p
The new monophosphonic acid directing group was successfully utilized in the Pd (II)-catalyzed ortho-arylation of benzylic phosphonic monoesters using potassium aryltrifluoroborates. A wide range of benzylic phosphonic monoesters underwent clean ortho-arylation in high yields, and excellent functional group tolerance was also observed.
Co-reporter:Kelvin Kau Kiat Goh, Sunggak Kim, and Samir Z. Zard
The Journal of Organic Chemistry 2013 Volume 78(Issue 23) pp:12274-12279
Publication Date(Web):November 1, 2013
DOI:10.1021/jo402169v
An efficient route leading to exclusively (1E,3E)-TMS dienes is described. Radical xanthate addition of keto-xanthates to vinyltrimethylsilane followed by one-pot Chugaev elimination/cyclization and in situ oxidation with m-CPBA afforded the corresponding TMS 2-sulfolenes. Isomerization to 3-sulfolenes by the action of DBU with the extrusion of sulfur dioxide in refluxing toluene gave the titled (1E,3E)-TMS dienes.
Co-reporter:Li Yan Chan, Xiangjian Meng, and Sunggak Kim
The Journal of Organic Chemistry 2013 Volume 78(Issue 17) pp:8826-8832
Publication Date(Web):August 5, 2013
DOI:10.1021/jo4011188
A simple and efficient method is developed for Pd-catalyzed ortho-acetoxylation using organophosphates, namely, benzylic phosphonic and aryl phosphoric monoacids, as the directing group.
Co-reporter:Li Yan Chan, Sunggak Kim, Youngchul Park, and Phil Ho Lee
The Journal of Organic Chemistry 2012 Volume 77(Issue 12) pp:5239-5244
Publication Date(Web):May 28, 2012
DOI:10.1021/jo300957q
A cheap, simple, and effective FeCl3-catalyzed Conia–ene cyclization of 2-alkynic 1,3-dicarbonyl compounds was stereospecific to afford alkylidenecyclopentanes in (E)-isomers via the 5-exo-dig pathway. The 5-endo-dig and 6-exo-dig cyclizations were also possible, depending on the structure of the substrates.
Co-reporter:Phil Ho Lee, Dongjin Kang, Subin Choi, and Sunggak Kim
Organic Letters 2011 Volume 13(Issue 13) pp:3470-3473
Publication Date(Web):June 9, 2011
DOI:10.1021/ol2012132
Trifluoromethanesulfonic acid catalyzed isomerization of kinetic enol derivatives to the thermodynamically favored isomers was developed. Under the present conditions, kinetic enol phosphates, enol acetates and benzoates, and enol sulfonates were smoothly isomerized to produce the corresponding thermodynamically favored isomers in good to excellent yields.
Co-reporter:Bathoju Chandra Chary, Sunggak Kim, Doosup Shin and Phil Ho Lee
Chemical Communications 2011 vol. 47(Issue 27) pp:7851-7853
Publication Date(Web):06 Jun 2011
DOI:10.1039/C1CC12052B
A new stereoselective synthesis of trisubstituted alkenes is developed. Hydrophosphoryloxylation of haloalkynes provides Z-alkenyl halophosphates, which undergo Pd-catalyzed consecutive cross-coupling reactions to afford regio- and stereodefined trisubstituted alkenes.
Co-reporter:Xiangjian Meng and Sunggak Kim
Organic & Biomolecular Chemistry 2011 vol. 9(Issue 12) pp:4429-4431
Publication Date(Web):13 May 2011
DOI:10.1039/C1OB05512G
Tungsten and molybdenum catalysts were employed to promote the cyclisation of N-propargylic amides to afford the corresponding oxazolines or oxazines via 5-exo-dig or 6-endo-dig mode.
Co-reporter:Bathoju Chra Chary;Wee Suan Low;Dr. Sunggak Kim;Dr. Hyunseok Kim;Dr. Phil Ho Lee
Chemistry – An Asian Journal 2011 Volume 6( Issue 8) pp:1970-1973
Publication Date(Web):
DOI:10.1002/asia.201100147
Co-reporter:Phil Ho Lee, Youngchul Park, Sangkyun Park, Euijae Lee, and Sunggak Kim
The Journal of Organic Chemistry 2011 Volume 76(Issue 3) pp:760-765
Publication Date(Web):January 12, 2011
DOI:10.1021/jo102441t
Pd-catalyzed multifold (2-, 3-, and 4-fold) carbon−sulfur cross-coupling reaction of indium tri(organothiolates) with polybromonated aromatic and heteroaromatic compounds was developed in a one-pot procedure. Both 2,5-dibromopyridine and 2,6-dibromopyridine reacted with indium tri(organothiolates) (0.68 equiv) in the presence of 4 mol % of Pd(OAc)2, 4.2 mol % of Xantphos, and 1 equiv of diisopropylethylamine (DIPEA), producing disulfides in good to excellent yields. These results indicate that indium tri(organothiolates) transfer all three alkyl- or arylthio groups attached to indium metal to electrophilic coupling partners. Indium tri(organothiolates) derived from alkyl thiol having a low boiling point, such as n-propyl, isopropyl, and tert-butyl thiol, acted as good nucleophilic coupling partners. In addition, indium tri(arylthiolates) derived from aryl thiols possessing an electron-withdrawing or -donating group on the aromatic ring participated well in the Pd-catalyzed multifold carbon−sulfur cross-coupling reaction. 4,4′-Dibromo-1,1′-biphenyl, 9,10-dibromoanthracene, 2,4-dibromoanisole, 2,7-dibromo-9,9-dimethylfluorene, 3,4-dibromothiophene, 2,3-dibromothiophene, 2,2′-bithiophene, 1,3,5-tribromobenzene, and 1,2,4,5-tetrabromobenzene were converted smoothly to the corresponding di-, tri-, and tetrasulfides.
Co-reporter:Sundae Kim, Nurul Ain Bte Kamaldin, Sol Kang and Sunggak Kim
Chemical Communications 2010 vol. 46(Issue 41) pp:7822-7824
Publication Date(Web):20 Sep 2010
DOI:10.1039/C0CC02081H
Sulfonyl oxime ethers undergo facile nucleophilic substitutions with various nucleophiles to yield the corresponding oxime ethers which provide an easy access to amines and carbonyl compounds.
Co-reporter:Jin Young Lee, Sundae Kim, Sunggak Kim
Tetrahedron Letters 2010 Volume 51(Issue 38) pp:4947-4949
Publication Date(Web):22 September 2010
DOI:10.1016/j.tetlet.2010.07.014
Enantioselective conjugate addition reactions of alkyl radicals to α′-phenylsulfonyl enones are described. A bis-oxazoline-zinc triflate complex proved to be an effective catalyst leading to high enantioselectivities and chemical yields.
Co-reporter:Dr. PhilHo Lee;Dr. Sundae Kim;Aeri Park;BathojuChra Chary;Dr. Sunggak Kim
Angewandte Chemie International Edition 2010 Volume 49( Issue 38) pp:6806-6809
Publication Date(Web):
DOI:10.1002/anie.201001799
Co-reporter:Sundae Kim, Nurul Ain Bte Kamaldin, Sol Kang and Sunggak Kim
Chemical Communications 2010 - vol. 46(Issue 41) pp:NaN7824-7824
Publication Date(Web):2010/09/20
DOI:10.1039/C0CC02081H
Sulfonyl oxime ethers undergo facile nucleophilic substitutions with various nucleophiles to yield the corresponding oxime ethers which provide an easy access to amines and carbonyl compounds.
Co-reporter:Xiangjian Meng and Sunggak Kim
Organic & Biomolecular Chemistry 2011 - vol. 9(Issue 12) pp:NaN4431-4431
Publication Date(Web):2011/05/13
DOI:10.1039/C1OB05512G
Tungsten and molybdenum catalysts were employed to promote the cyclisation of N-propargylic amides to afford the corresponding oxazolines or oxazines via 5-exo-dig or 6-endo-dig mode.
Co-reporter:Bathoju Chandra Chary, Sunggak Kim, Doosup Shin and Phil Ho Lee
Chemical Communications 2011 - vol. 47(Issue 27) pp:NaN7853-7853
Publication Date(Web):2011/06/06
DOI:10.1039/C1CC12052B
A new stereoselective synthesis of trisubstituted alkenes is developed. Hydrophosphoryloxylation of haloalkynes provides Z-alkenyl halophosphates, which undergo Pd-catalyzed consecutive cross-coupling reactions to afford regio- and stereodefined trisubstituted alkenes.
Co-reporter:Bathoju Chandra Chary and Sunggak Kim
Organic & Biomolecular Chemistry 2013 - vol. 11(Issue 40) pp:NaN6882-6882
Publication Date(Web):2013/08/20
DOI:10.1039/C3OB41548A
Rhodium(III)-catalyzed C–H olefination of aryl phosphonic esters is reported for the first time. In this mild and efficient process, the phosphonic ester group is utilized successfully as a new directing group. In addition, mono-olefination for aryl phosphonates is observed using a phosphonic diamide directing group.
Co-reporter:Li Yan Chan, Sunggak Kim, Taekyu Ryu and Phil Ho Lee
Chemical Communications 2013 - vol. 49(Issue 41) pp:NaN4684-4684
Publication Date(Web):2013/04/11
DOI:10.1039/C3CC41107A
A highly efficient Pd-catalyzed ortho-alkenylation is reported using a mono-phosphoric acid-directing group for the first time. This phosphoric acid-directing group is successfully utilized for the synthesis of various alkenylated products and offers a new approach to transition-metal-catalyzed C–H activation.