Enantiomerically Enriched (4+3) Cycloadducts from Optically Active Epoxy Enolsilanes

Abstract

Pure chemistry: Intermolecular (4+3) cycloadditions of optically active epoxy enolsilanes and dienes afford cycloadducts with near complete conservation of enantiomeric purity, in up to 99 % ee. This reaction is a general method to obtain optically active bicyclic compounds for synthesis. TESOTf=triethylsilyl trifluoromethanesulfonate.

Dearomative Intramolecular (4+3) Cycloadditions of Thiophenes

“…[30] Our group has a long-standing interest in the (4+3) cycloadditions of epoxy and aziridinyl enolsilanes with dienes. [31][32][33][34][35][36][37][38] These (4+3) cycloadditions have achieved the dearomatization of arenes and heteroaromatics to afford bridged cycloheptanes. As it is clear that dearomative cycloadditions of thiophene are neither expected nor common, whether this kind of substrate could be within the scope of this reaction was uncertain.…”