Enantioselective α-Chlorination of Aldehydes with Recyclable Fluorous (S)-Pyrrolidine-Thiourea Bifunctional Organocatalyst
作者:Chun Cai、Wei Zhang、Liang Wang、Dennis Curran
DOI:10.1055/s-0029-1219198
日期:2010.2
A novel fluorous (S)-pyrrolidine-thiourea bifunctional organocatalyst is prepared. The catalyst shows good activity and enantioselectivity for direct α-chlorination of aldehydes using N-chlorosuccinimide (NCS) as the chlorine source. It can be recovered from the reaction mixture by fluorous solid-phase extraction with excellent purity for direct reuse.
Novel 3-aminopyrrolidine derivatives were synthesized and evaluated for their antagonistic activity against human chemokine receptor 2. Structure-activity studies on 3-aminopyrrolidine incorporating heteroatomic carbocycle moieties led to piperidine compound 19, and piperazine compounds 42, 47 and 49 as highly potent hCCR2 antagonists. (C) 2010 Elsevier Ltd. All rights reserved.
Demonstration of a Phosphazirconocene as a Catalyst for the Ring Opening of Epoxides with TMSCl
作者:Li-Sheng Wang、T. Keith Hollis
DOI:10.1021/ol034816r
日期:2003.7.1
[GRAPHIC]In this study, it was demonstrated for the first time that a phosphazirconocene catalyzes the ring opening of epoxides with TMSCI. This reactivity leads to a facile preparation of chlorohydrins. The late transition metal Fe analogue was found to catalyze the reaction at rates and stereoselectivity comparable to those of the Zr complex.