Copper-catalyzed propargylation of diborylmethane.

A Cu/PPh3-catalyzed propargylic substitution reaction of diborylmethane is reported. Different substituted propargyl electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. Di-deuterated diborylmethane can also be used under these conditions and generates α-deuterated alkylboronic esters in good yield.