Cationic-Oxazaborolidine-Catalyzed Enantioselective Diels-Alder Reaction of α,β-Unsaturated Acetylenic Ketones
作者:Joshua N. Payette、Hisashi Yamamoto
DOI:10.1002/anie.200904339
日期:2009.10.12
Yne also a good dienophile: The cationic oxazaborolidine 1 promoted the formation of Diels–Alder adducts between acetylenic ketones and both cyclic and acyclic dienes in excellent yield with 99 % ee (see scheme; Tf=trifluoromethanesulfonyl, TMS=trimethylsilyl). Importantly, high levels of asymmetric induction were also observed with dienophiles that lacked the typical hydrogen‐bonding motif required