Enantioselective Organocatalytic α-Alkylation of Ketones by SN1-Type Reaction of Alcohols
作者:Maria Trifonidou、Christoforos G. Kokotos
DOI:10.1002/ejoc.201101509
日期:2012.3
The enantioselective α-alkylation reaction of cyclic ketones is described. Our catalyst, based on a “privileged” pyrrolidine ring bearing a chiral thioxotetrahydropyrimidinone ring, is a highly reactive catalyst for cyclic ketones. When this catalyst was coupled with in situ generated carbocations derived from alcohols, the corresponding α-alkylated adducts were obtained in moderate to quantitative
Pyrrolidine-derived functionalizedchiralionicliquids (FCILs) have been found to catalyzeasymmetric S N 1 α-alkylations of ketones and aldehydes with up to 99 % yield, >99:1 dr and 87 % ee. The FCIL catalysts enable S N 1 α-alkylations of cyclicketones, particularly of 3- and 4-substituted cyclohexanones with excellent diastereoselectivity and good enantioselectivity, featuring unprecedented desymmetrization
已发现吡咯烷衍生的官能化手性离子液体 (FCIL) 可催化酮和醛的不对称 SN 1 α-烷基化反应,产率高达 99%,>99:1 dr 和 87% ee。FCIL 催化剂使环酮,特别是 3-和 4-取代环己酮的 SN 1 α-烷基化具有优异的非对映选择性和良好的对映选择性,为这些类型的不对称反应提供了前所未有的去对称化和动力学拆分过程。介绍了这项研究的全部细节以及提议的烯胺过渡态。