Catalytic asymmetric cyclopropanation of sulfoxonium ylides catalyzed by a chiral-at-metal rhodium complex

An efficient asymmetric cyclopropanation of sulfoxonium ylides with alpha,beta-unsaturated 2-acyl imidazoles catalyzed by a chiral-at-metal rhodium complex has been developed. The enantioenriched cyclopropane derivatives bearing three contiguous tertiary stereocenters were obtained in generally high yields (up to 98%) with excellent stereoselectivities (up to >20 : 1 dr, >99% ee). Remarkably, as low as 0.1 mol% of the chiral Rh(iii) complex can realize a scale-up reaction with excellent yield and enantioselectivity.

Automated summary

An efficient asymmetric cyclopropanation reaction has been developed, which involves the reaction of sulfoxonium ylides with alpha,beta-unsaturated 2-acyl imidazoles catalyzed by a chiral-at-metal rhodium complex. The enantioenriched cyclopropane derivatives, containing three contiguous tertiary stereocenters, were obtained with high yields and excellent stereoselectivities.