Enantioselective Acyloin Rearrangement of Acyclic Aldehydes Catalyzed by Chiral Oxazaborolidinium Ion

A catalytic enantioselective acyloin rearrangement of acyclic aldehydes to synthesize highly optically active acyloin derivatives is described. In the presence of a chiral oxazabor-olidinium ion catalyst, the reaction provided chiral alpha-hydroxy aryl ketones in high yield (up to 95%) and enantioselectivity (up to 98% ee). In addition, the enantioselective acyloin rearrangement of alpha,alpha-dialkyl-alpha-siloxy aldehydes produced chiral alpha-siloxy alkyl ketones in high yield (up to 92%) with good enantioselectivity (up to 89% ee).

Automated summary

A catalytic enantioselective acyloin rearrangement is utilized to synthesize highly optically active acyloin derivatives, yielding chiral alpha-hydroxy aryl ketones and chiral alpha-siloxy alkyl ketones with high yields and good enantioselectivity.