Highly enantioselective immobilized prolinamide-catalyzed aldol reactions in continuous-flow systems: effect of water on the catalyst lifetime and application in the synthesis of a chiral fenpentadiol analogue

被引：13

作者：

Yue, Caizhen ^{[1
]}

Yamashita, Yasuhiro ^{[1
]}

Kobayashi, Shu ^{[1
]}

机构：

[1] Univ Tokyo, Sch Sci, Dept Chem, Bunkyo Ku, Tokyo 1130033, Japan

来源：

GREEN CHEMISTRY | 2021年 / 23卷 / 05期

基金：

日本学术振兴会;

关键词：

Enantioselectivity - Condensation reactions;

D O I：

10.1039/d0gc04202a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Catalytic enantioselective aldol reactions of trifluoroacetophenones with ketones under continuous-flow conditions have been developed for the first time by using polystyrene-supported prolinamides. The robustness of the flow system was demonstrated by the continuous synthesis of a variety of trifluoromethyl carbinols in high yields with high enantioselectivities. The unusually long lifetimes (>195 h) of this flow process were achieved by facilitating H2O-promoted hydrolysis of iminium intermediates on the polymer. Mechanistic study revealed a racemization phenomenon and an inherent reversible property of the aldol reactions in a conventional batch system, both of which were suppressed under continuous-flow conditions. The synthetic utility of this flow process was further demonstrated by the formal continuous-flow synthesis of a chiral fenpentadiol analogue.

引用

页码：1989 / 1994

页数：6