Highly enantioselective synthesis of chiral 7-ring O- and N-heterocycles by a one-pot nitro-Michael–cyclization tandem reaction
作者:Renate Rohlmann、Constantin-Gabriel Daniliuc、Olga García Mancheño
DOI:10.1039/c3cc47397j
日期:——
concise enantioselective approach to synthesise medium-sized 7-ring O- and N-heterocycles has been developed. The synthetic strategy relies on an organocatalytic nitro-Michael-nitrile oxide cycloaddition tandemreaction, leading to the corresponding chiral benzoxe- and benzazepine derivatives containing an additional fused dihydroisoxazoline ring in good yields and excellent enantioselectivities (up to
Preparation of Functional Benzofurans, Benzothiophenes, and Indoles Using Ester, Thioester, and Amide via Intramolecular Wittig Reactions
作者:Siang-en Syu、Yu-Ting Lee、Yeong-Jiunn Jang、Wenwei Lin
DOI:10.1021/ol201062r
日期:2011.6.3
Preparation of new types of highly functional benzofurans, benzothiophenes, and indoles is realized via intramolecular Wittig reactions with the corresponding ester, thioester, and amide functionalities. The key intermediates, phosphorus ylides, presumably result from the addition of Bu3P toward aldehydes followed by acylation and deprotonation. Synthesis of functional benzofurans directly starting