Cooperative N-Heterocyclic Carbene/Lewis Acid Catalysis for Highly Stereoselective Annulation Reactions with Homoenolates

被引：257

作者：

Cardinal-David, Benoit ^{[1
]}

Raup, Dustin E. A. ^{[1
]}

Scheidt, Karl A. ^{[1
]}

机构：

[1] Northwestern Univ, Dept Chem, Ctr Mol Innovat & Drug Discovery, Chem Life Proc Inst, Evanston, IL 60208 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2010年 / 132卷 / 15期

关键词：

GAMMA-BUTYROLACTONES; ALPHA; BETA-UNSATURATED ALDEHYDES; ENALS; UMPOLUNG; CHALCONES;

D O I：

10.1021/ja910666n

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

A new approach that takes advantage of N-heterocyclic carbene/Lewis acid cooperative catalysis provides access to cis-1,3,4-trisubstituted cyclopentenes from enals and chalcone derivatives with high levels of diastereoselectivity and enantioselectivity. The presence of Ti(O/Pr)(4) as the Lewis acid allows for efficient substrate preorganization, which translates into high levels of diastereoselectivity. Additionally, we demonstrate the possibility of controlling the absolute stereochemistry of NHC-catalyzed reactions by employing a catalytic amount of a chiral Lewis acid as the unique source of optically active promoter.

引用

页码：5345 / +

页数：4

共 41 条

[1] Looking for stable carbenes: The difficulty in starting anew [J].