Asymmetric (4+3) Cycloadditions of Enantiomerically Enriched Epoxy Enolsilanes
作者:Brian Lo、Sarah Lam、Wing-Tak Wong、Pauline Chiu
DOI:10.1002/anie.201207427
日期:2012.11.26
A f(oxy) allyl: The intermolecular (4+3) cycloaddition of enantiomericallyenriched epoxy enolsilanes produces cycloadducts with up to 99 % ee, thus implying the reaction does not proceed by the putative achiral oxyallyl cation intermediate, but through a transiently chiral electrophile which retains the stereochemical information of the epoxide (see scheme; TES=triethylsilyl, Tf=trifluoromethanesulfonyl)