Isothiourea-Catalyzed Enantioselective Functionalization of 2-Pyrrolyl Acetic Acid: Two-Step Synthesis of Stereodefined Dihydroindolizinones
作者:Shuyue Zhang、James E. Taylor、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/acs.orglett.8b02423
日期:2018.9.7
Catalytic enantioselective functionalization of 2-pyrrolyl acetic acid with trichloromethyl enones using isothiourea catalysis is reported, leading to a range of stereodefined diesters and diamides after nucleophilic ring opening with either methanol or benzylamine (30 examples, up to >95:5 dr and >99:1 er). Subsequent intramolecular Friedel–Crafts reaction allows access to dihydroindolizinones in high yields
据报道,使用异硫脲催化三氯甲基烯酮对2-吡咯基乙酸的催化对映选择性官能化,导致在用甲醇或苄基胺亲核开环后产生一系列立体定义的二酯和二酰胺(30个实例,高达> 95:5 dr和> 99 :1 er)。随后的分子内Friedel-Crafts反应可实现高收率和立体保真度的二氢吲哚并酮(6个实例,高达> 95:5 dr和99:1 er)。