first highly enantioselective and regiodivergent conjugate addition of trialkylaluminium reagents to nitrodienes and nitroenynes is described. By a design of the substrate and a fine-tuning of the reaction conditions, it is possible to selectively form the 1,4- or 1,6-adduct. The same combination of catalyst, copper source, and a ferrocene-based phosphine ligand afforded enantioselectivities up to 95%
Sequential Au(<scp>i</scp>)/chiral tertiary amine catalysis: a tandem C–H functionalization of anisoles or a thiophene/asymmetric Michael addition sequence to quaternary oxindoles
作者:Zhong-Yan Cao、Yu-Lei Zhao、Jian Zhou
DOI:10.1039/c5cc10096h
日期:——
We report an unprecedented sequential Au(I)/bifunctional tertiary amine catalysis, which enables a tandem C-H functionalization of weak nucleophiles (anisole or thiophene) and asymmetric Michael addition for the highly enantioselective synthesis...
using traditional alkylation methods under basic conditions. The approach enables a highly stereoselective synthesis of quaternary (thio)oxindoles via a formal allylation-asymmetric Michaeladdition sequence. These adducts are versatile synthons for spirocyclic (thio)oxindoles. Initial biological studies reveal that chiral thiooxindoles show promising antiproliferation activity that is better than that
CF<sub>3</sub>CO<sub>2</sub>H-Catalyzed Synthesis of 3-Alkynylpyrrole Derivatives and Their Controlled Reduction
作者:Yulei Zhao、Xuqiang Guo、Ruihua Zhang、Shuai Li、Tingting Chen、Xuejun Sun
DOI:10.1021/acs.joc.1c02078
日期:2021.11.5
3-alkynylpyrrole derivatives. This mild cyclization reaction might proceed through the nucleophilic addition, intramolecular cyclization, and the subsequent elimination processes. The protocol features a broad substrate scope, good selectivity, and functional group tolerance. Notably, the advantage of this method is also highlighted by the controlled reduction to generate alkenyl- or alkylpyrrole derivatives in