钛催化的螺环吲哚恶唑啉的立体选择性合成。

Titanium-catalyzed stereoselective synthesis of spirooxindole oxazolines.

机构信息

Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.

出版信息

Org Lett. 2011 Feb 4;13(3):418-21. doi: 10.1021/ol1027305. Epub 2010 Dec 27.

Abstract

A regio- and stereoselective cyclization between isatins and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (10 or 20 mol %) to afford spiro[3,3'-oxindoleoxazolines] in excellent yield (up to 99%) and diastereoselectivity (dr >99:1). Substitution at the 4-position of the oxazole controls nucleophilic attack to provide either the 2-oxazoline or 3-oxazoline spirocycle with excellent (>99:1) regiocontrol.

摘要

已开发出一种使用催化四氯化钛（10 或 20 mol %）的色满和 5-甲氧基恶唑之间的区域和立体选择性环化反应，以优异的收率（高达 99%）和非对映选择性（dr >99:1）得到螺[3,3'-氧化吲哚恶唑啉]。恶唑 4-位的取代基控制亲核进攻，可提供具有优异（>99:1）区域选择性的 2-恶唑啉或 3-恶唑啉螺环。