Enantioselective Cyclopropanation of Allenes Catalyzed by a Rhodium(II) Complex

Significance

The authors reported the rhodium-catalyzed enantioselective cyclopropanation of ­allenes with methyl aryldiazoacetate to afford alkylidene cyclopropanes. The cyclopropane products of monosubstituted allene substrates were obtained in good yields, while yields for 1,1-disubstituted allenes were significantly lower. Interestingly, the substitution with silicon on the allene substrate has a strong accelerating effect on the reaction.