一种新型路易斯酸催化的[3,3] - 迁移重排反应的发展：联烯酸酯 - 克莱森重排反应

Development of a new Lewis acid-catalyzed [3,3]-sigmatropic rearrangement: the allenoate-Claisen rearrangement.

作者信息

Lambert Tristan H, MacMillan David W C

机构信息

Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.

出版信息

J Am Chem Soc. 2002 Nov 20;124(46):13646-7. doi: 10.1021/ja028090q.

DOI:10.1021/ja028090q

PMID:12431073

Abstract

A new Lewis acid-catalyzed Claisen rearrangement has been developed that allows the stereoselective construction of beta-amino-alpha,beta,epsilon,zeta-unsaturated-gamma,delta-disubstituted esters from simple allylic amines and allenoate esters. This reaction, which is contingent upon the use of Lewis acid, can be conducted with a range of metal salts (Yb(OTf)3, AlCl3, Sn(OTf)2, Cu(OTf)2, MgBr2.Et2O, FeCl3, Zn(OTf)2) with catalyst loadings as low as 5 mol %. This catalytic process provides access to a diverse range of beta-amino-alpha,beta,epsilon,zeta-unsaturated-gamma,delta-disubstituted esters in high yield and with excellent levels of diastereoselectivity for a series of allyl pyrrolidines (R1 = H, Me, i-Pr, Ph, NR2 = pyrrolidine, piperidine, NMe2; >/=81% yield, >/=94:6 syn:anti) and allenoate esters (R2 = H, Me, i-Pr, Ph, allyl, NPht, Cl; >/=75% yield, >/=91:9 syn:anti). The capacity of this new Claisen rearrangement to provide catalytic access to elusive structural motifs has also been demonstrated in the stereospecific formation of quaternary carbon bearing frameworks arising from geranyl- and neryl pyrrolidine (>/=93% yield, >98:2 dr).

摘要

已开发出一种新型路易斯酸催化的克莱森重排反应，该反应可从简单的烯丙基胺和联烯酸酯立体选择性地构建β-氨基-α,β,ε,ζ-不饱和-γ,δ-二取代酯。此反应依赖于路易斯酸的使用，可使用一系列金属盐（Yb(OTf)3、AlCl3、Sn(OTf)2、Cu(OTf)2、MgBr2·Et2O、FeCl3、Zn(OTf)2）进行，催化剂负载量低至5 mol%。该催化过程能够以高产率和优异的非对映选择性获得多种β-氨基-α,β,ε,ζ-不饱和-γ,δ-二取代酯，适用于一系列烯丙基吡咯烷（R1 = H、Me、i-Pr、Ph，NR2 = 吡咯烷、哌啶、NMe2；产率≥81%，非对映体比例≥94:6顺式:反式）和联烯酸酯（R2 = H、Me、i-Pr、Ph、烯丙基、NPht、Cl；产率≥75%，非对映体比例≥91:9顺式:反式）。这种新型克莱森重排反应在从香叶基和橙花基吡咯烷立体定向形成含季碳骨架方面也展示了其提供催化获得难以捉摸的结构基序的能力（产率≥93%，非对映体比例>98:2）。