Copper-Catalyzed Diastereo- and Enantioselective Desymmetrization of Cyclopropenes: Synthesis of Cyclopropylboronates

A novel Cu-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes to afford nonracemic cyclo­propyl­boronates is described. Trapping the cyclo­propyl­copper intermediate with electrophilic amines allows for the synthesis of cyclo­propyl­amino­boronic esters and demonstrates the potential of the approach for the synthesis of functionalized cyclopropanes.