Organocatalytic Asymmetric Sulfa-Michael Addition of Thiols to α,β-Unsaturated Hexafluoroisopropyl Esters: Expeditious Access to (<i>R</i>)-Thiazesim
作者:Xin Fang、Jun Li、Chun-Jiang Wang
DOI:10.1021/ol4015305
日期:2013.7.5
A highly efficient organocatalytic asymmetric SMA reaction of hexafluoroisopropyl alpha,beta-unsaturated esters has been developed. Introducing electron-withdrawing hexafluoroisopropyl ester is crucial to enhancing the electrophilicity of unsaturated esters as SMA acceptors. The catalytic system performs well over a broad scope of alpha,beta-unsaturated esters and diversified thiols and provides facile access to (R)-thiazesim in a one-pot protocol.
Steric Tuning of Reactivity and Enantioselectivity in Addition of Thiophenol to Enoates Catalyzed by an External Chiral Ligand
Structural requirements of a chiral ligand for the catalytic asymmetric addition of thiophenol to α,β-unsaturated esters
作者:Kiyoshi Tomioka、Manabu Okuda、Katsumi Nishimura、Shino Manabe、Motomu Kanai、Yasuo Nagaoka、Kenji Koga
DOI:10.1016/s0040-4039(98)00080-x
日期:1998.4
The tridentate amino ether ligands 1 and 14 were developed through systematic structural modification of the bidentate diether ligand 2. The reaction of thiophenol with methyl crotonate was catalyzed by 14 and lithium thiophenolate to afford (S)-methyl 3-phenylthiobutanoate in 75% ee and 95% yield. (C) 1998 Elsevier Science Ltd. All rights reserved.
PUZICHA, GISBERT;LEVAI, ALBERT;SZILAGYI, LASZLO, MONATSH. CHEM., 119,(1988) N-9, C. 933-944