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Direct Asymmetric Aldol Reaction Co‐catalyzed by Amphiphilic Prolinamide Phenol and Lewis Acidic Metal on Water
Author(s) -
Zhang Tao,
Zhang Yunxiao,
Li Zaichun,
Song Zhongtai,
Liu Hao,
Tao Jingchao
Publication year - 2013
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201201017
Subject(s) - chemistry , aldol reaction , catalysis , lewis acids and bases , phenol , amphiphile , alkali metal , stereoselectivity , transition metal , lewis acid catalysis , metal , enantioselective synthesis , chloride , organic chemistry , copolymer , polymer
An approach based on combinations of various water compatible Lewis acids and lipophilic group containing amphiphilic prolinamide co‐catalysts has been evaluated for the direct asymmetric Aldol reaction. From the broad screening of chloride salts from alkali metal to transition metal, LiCl, ZnCl 2 and SnCl 2 lead to the highest stereoselectivities. The optimized catalytic conditions (10 mol% prolinamide with 10 mol% MCl 2 or 20 mol% LiCl at room temperature on water) gave anti ‐products with improved enantioselectivities (up to 99% ee ) compared to the moderately stereoselective procedure based on prolinamide activation only.