Diastereoselective Friedel-Crafts alkylation of indoles with chiral (α-phenyl benzylic cations.: Asymmetric synthesis of anti-1,1,2-triarylalkanes

被引：48

作者：

Chung, John Y. L. ^{[1
]}

Mancheno, Danny ^{[1
]}

Dormer, Peter G. ^{[1
]}

Variankaval, Narayan ^{[1
]}

Ball, Richard G. ^{[1
]}

Tsou, Nancy N. ^{[1
]}

机构：

[1] Merck Res Labs, Rahway, NJ 07065 USA

来源：

ORGANIC LETTERS | 2008年 / 10卷 / 14期

关键词：

D O I：

10.1021/ol800858c

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The reactions of chiral benzyl carbocations bearing a-phenyl substituents with N-sulfonylated indoles afford 1,1,2-triarylalkanes with ante selectivities. This outcome is a reversal of facial diastereoselectivity relative to Bach's (x-alkyl-bearing benzyl cations. The reactions are promoted by either a Bronsted acid (TFA) or Lewis acid (BF(3)center dot OEt(2)), offering differential diastereoselectivities and reactivities. The electronic properties of both reacting partners strongly influence the reaction rates and the product diastereoselectivities and appear to operate under kinetic control. This chemistry provides an efficient access to sterically congested tetrasubstituted ethanes.

引用

页码：3037 / 3040

页数：4

共 27 条

[1] CATIONIC CYCLIZATION REACTIONS INITIATED BY STABILIZED BENZYL CATIONS [J].