通过碘介导的开环反应实现钪（III）催化的N-苯甲酰基环丙烷甲酰胺的羟醛型加成反应：γ-内酰胺的立体选择性合成

Sc3+-catalyzed aldol-type additions of N-benzoylcyclopropanecarboxamides via iodide-mediated ring-opening: stereoselective synthesis of gamma-lactams.

作者信息

Wiedemann Sean H, Noda Hidetoshi, Harada Shinji, Matsunaga Shigeki, Shibasaki Masakatsu

机构信息

Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan.

出版信息

Org Lett. 2008 Apr 17;10(8):1661-4. doi: 10.1021/ol800401g. Epub 2008 Mar 18.

DOI:10.1021/ol800401g

PMID:18345682

Abstract

A new catalytic aldol-type addition of cyclopropanecarboximides to aldehydes via iodide-mediated ring-opening is presented. The reaction was found to be catalyzed at 0 degrees C using either a Sc(OTf)3/NaI system or ScI3. Stereoselective formation of alpha,alpha-disubstituted enolates occurred in situ. gamma-Lactams bearing alpha-carbonyl quaternary stereocenters were obtained in 97-57% yield and dr = 90:10-80:20 after ring closure.

摘要

本文报道了一种通过碘介导的开环反应，将环丙烷甲酰胺与醛进行新型催化羟醛型加成反应。研究发现，使用Sc(OTf)3/NaI体系或ScI3在0℃下可催化该反应。原位发生α,α-二取代烯醇盐的立体选择性形成。环化后，得到了具有α-羰基季碳立体中心的γ-内酰胺，产率为97%-57%，非对映体比例为90:10-80:20。