Preparation of Functional Benzofurans, Benzothiophenes, and Indoles Using Ester, Thioester, and Amide via Intramolecular Wittig Reactions

• DOI: 10.1021/ol201062r
• Publication Date: 2011-05-12T14:51:26Z
• Authors: Siang-en Syu; Yu-Ting Lee; Yeong-Jiunn Jang; Wenwei Lin
• Keywords: Thioester; Wittig reaction; Amide

Preparation of new types highly functional benzofurans, benzothiophenes, and indoles is realized via intramolecular Wittig reactions with the corresponding ester, thioester, amide functionalities. The key intermediates, phosphorus ylides, presumably result from addition Bu3P toward aldehydes followed by acylation deprotonation. Synthesis benzofurans directly starting salicylic aldehyde derivatives acid chlorides in a one-step procedure also developed.