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.