脯氨酸原位制备的 N-氧化物作为双功能有机催化剂催化 α,α-二烷氧基酮的对映选择性氰基硅烷化反应。

Enantioselective cyanosilylation of alpha,alpha-dialkoxy ketones catalyzed by proline-derived in-situ-prepared N-oxide as bifunctional organocatalyst.

作者信息

Qin Bo, Liu Xiaohua, Shi Jian, Zheng Ke, Zhao Haitao, Feng Xiaoming

机构信息

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.

出版信息

J Org Chem. 2007 Mar 30;72(7):2374-8. doi: 10.1021/jo062336i. Epub 2007 Mar 6.

DOI:10.1021/jo062336i

PMID:17338569

Abstract

Bifunctional N,N'-dioxide catalysts have been developed for highly enantioselective cyanosilylation of alpha,alpha-dialkoxy ketones. This process, catalyzed by in-situ-prepared proline-derived N,N'-dioxide 2b, produced the corresponding cyanohydrin trimethylsilyl ethers in excellent yields (up to 99%) with high enantioselectivities (up to 93% ee). A reasonable mechanism was proposed according to the observation of the linear effect, 1H NMR spectra, isolated cyanohydrin, and the roles of the NH and N-oxide moieties of the catalyst.

摘要

已开发出双功能N，N'-二氧化物催化剂用于α，α-二烷氧基酮的高对映选择性氰基硅烷化反应。该反应由原位制备的脯氨酸衍生的N，N'-二氧化物2b催化，以优异的产率（高达99%）和高对映选择性（高达93% ee）生成相应的氰醇三甲基硅基醚。根据线性效应、1H NMR光谱、分离得到的氰醇以及催化剂的NH和N-氧化物部分的作用，提出了合理的反应机理。