Mechanistic investigation of the 2,5-diphenylpyrrolidine-catalyzed enantioselective α-chlorination of aldehydes

被引：66

作者：

Halland, N ^{[1
]}

Lie, MA ^{[1
]}

Kjærsgaard, A ^{[1
]}

Marigo, M ^{[1
]}

Schiott, B ^{[1
]}

Jorgensen, KA ^{[1
]}

机构：

[1] Aarhus Univ, Danish Natl Res Fdn, Ctr Catalysis, Dept Chem, DK-8000 Aarhus, Denmark

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2005年 / 11卷 / 23期

关键词：

asymmetric catalysis; chlorination; density functional calculations; isotope effects; kinetics; sigmatropic rearrangement;

D O I：

10.1002/chem.200500776

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The mechanism for the 2,5diphenylpyrrolidine-catalyzed enantio-selective alpha-chlormation of aldehydes with electrophilic halogenation reagents has been investigated by using experimental and computational methods. These studies have led us to propose a mechanism for the reaction that proceeds through an initial N-chlorination of the chiral catalyst-substrate complex, followed by a 1,3-sigmatropic shift of the chlorine atom to the enamine carbon atom. The sugested reaction course is different from previously proposed mechanisms for organocatalytic enamine reactions, in which the carbon-electrophile bond is formed directlv Furthermore, the rate-determining step in the overall reaction was determined and the presence of nonlinear effects was probed.

引用

页码：7083 / 7090

页数：8

共 88 条

[1] The direct catalytic asymmetric cross-aldol reaction of aldehydes [J].