Highly Enantioselective Epoxidation of 2,4‐Diarylenones by Using Dimeric Cinchona Phase‐Transfer Catalysts: Enhancement of Enantioselectivity by Surfactants

Dramatic increases in reaction rates and enantioselectivities can be effected by the use of surfactants for the phase-transfer catalytic epoxidation of aromatic enones. Based on the X-ray crystal structure of the most effective catalyst—a modified cinchona alkaloid—a plausible transition state of the reaction has been modeled (see picture; HOO− yellow, C gray, H white, N blue, O red).