Guoqiang Yang
Shanghai Jiao Tong University
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Publication
Featured researches published by Guoqiang Yang.
Journal of the American Chemical Society | 2014
Guoqiang Yang; Petra Lindovska; Dajian Zhu; Justin Kim; Peng Wang; Ri-Yuan Tang; Mohammad Movassaghi; Jin-Quan Yu
meta-C-H olefination, arylation, and acetoxylation of indolines have been developed using nitrile-containing templates. The combination of a monoprotected amino acid ligand and the nitrile template attached at the indolinyl nitrogen via a sulfonamide linkage is crucial for the meta-selective C-H functionalization of electron-rich indolines that are otherwise highly reactive toward electrophilic palladation at the para-positions. A wide range of synthetically important and advanced indoline analogues are selectively functionalized at the meta-positions.
Angewandte Chemie | 2013
Guoqiang Yang; Wanbin Zhang
Sly as Nicox: A palladium-catalyzed addition of arylboronic acids to ketimines has been developed to efficiently provide products in up to 99 % yield and 96 % ee. The reactions could be run under aerobic conditions and with unpurified trifluoroethanol (TFE). A pyrrolidine compound bearing a chiral α-tertiary amine was synthesized in several steps without loss of enantioselectivity. TFA = trifluoroacetate.
Angewandte Chemie | 2014
Xiaohong Huo; Guoqiang Yang; Delong Liu; Yangang Liu; Ilya D. Gridnev; Wanbin Zhang
Allylic alcohols were directly used in Pd-catalyzed allylic alkylations of simple ketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co-catalyst, and a hydrogen-bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the π-allylpalladium complex by lowering the activation barrier.
Angewandte Chemie | 2012
Guoqiang Yang; Chaoren Shen; Wanbin Zhang
Its all in the solvent: An enantioselective variant of an aza-Wacker-type cyclization that gives isoindolinones containing tetrasubstituted carbon centers α to the nitrogen atom has been developed (see scheme; tfa=trifluoroacetate). The use of a highly coordinating solvent is crucial for the activity of the catalyst and the stereoselectivity the reaction (up to 99 % ee).
Angewandte Chemie | 2015
Dajian Zhu; Guoqiang Yang; Jian He; Ling Chu; Gang Chen; Wei Gong; Ke Chen; Martin D. Eastgate; Jin-Quan Yu
2,4,6-Trimethoxypyridine is identified as an efficient ligand for promoting a Pd-catalyzed ortho-C-H amination of both benzamides and triflyl-protected benzylamines. This finding provides guidance for the development of ligands that can improve or enable Pd(II)-catalyzed Csp2-H activation reactions directed by weakly coordinating functional groups.
Organic Letters | 2014
Xiaohong Huo; Mao Quan; Guoqiang Yang; Xiaohu Zhao; Delong Liu; Yangang Liu; Wanbin Zhang
C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylic alkylation using only alcohol solvents. This procedure does not require any additives and proceeds with high regioselectivity. The applicability of this transformation to a variety of functionalized allylic ether substrates was also investigated. Furthermore, this methodology can be easily extended to the asymmetric synthesis of enantiopure products (99% ee).
Organic Letters | 2012
Guoqiang Yang; Wanbin Zhang
A switchable regioselective intramolecular aerobic aza-Wacker cyclization catalyzed by palladium is presented. Isoindolinones or isoquinolin-1(2H)-ones could be prepared selectively from the same substrates using different catalysts. The type and steric hindrance of the ligands may be the variables most significant for regiocontrol.
Organic Letters | 2016
Qun He; Liang Wu; Xuezhen Kou; Nicholas Butt; Guoqiang Yang; Wanbin Zhang
A Pd(II)/Pyrox-catalyzed enantioselecitve addition of arylboronic acids to 3-ketimino oxindoles was developed, providing chiral 3-amino-2-oxindoles with a quaternary stereocenter in high yields and with good enantioselectivities. A variety of functionalized 3-ketimino oxindoles can be used, and the method tolerates some variation in arylboronic acid scope. This asymmetric arylation provides an alternative efficient catalytic method for the preparation of chiral 3-aryl-3-amino-2-oxindoles, which also represents the first example of a Pd(II)-catalyzed addition of arylborons to exocyclic ketimines.
Organic chemistry frontiers | 2015
Mao Quan; Guoqiang Yang; Fang Xie; Ilya D. Gridnev; Wanbin Zhang
A palladium-catalyzed asymmetric arylation of cyclic N-sulfonyl ketimine esters is described. The desired products could be prepared with excellent yields (up to 99%) and enantioselectivities (up to 99% ee) under mild reaction conditions. Furthermore, a possible reaction mechanism was determined using DFT calculations.
Organic Letters | 2013
Chaoren Shen; Guoqiang Yang; Wanbin Zhang
The insertion of arynes into arylphosphoryl amide bonds to synchronously construct C-P and C-N bonds is described. Arynes generated in situ from o-triflate arylsilanes under fluoride-promoted conditions insert into relatively inert P-N bonds, producing o-amine-substituted arylphosphine oxides. This process provides a simple pathway for the preparation of precursors for a number of bidentate aminophosphine ligands.