Cu-catalyzed coupling of vinylidene cyclopropanes with allyl and allenyl boronates.

The development of Cu-catalyzed coupling of vinylidene cyclopropanes with allyl or allenyl boronates is reported. The reaction forms a C–C bond at the terminal carbon atom of the allene moiety of vinylidene cyclopropanes with concurrent opening of the cyclopropane ring. In addition, the resulting Cu-enolate intermediate can be intercepted by external electrophiles.