Regioselective synthesis of branched alkenylborons via copper-catalyzed protoborylation of 1,4-diynes

A copper-catalyzed highly regioselective protoborylation of 1,4-diynes for the synthesis of alkenylboramide compounds was reported. Various (hetero)aryl and alkyl substituted terminal 1,4-diynes afforded the corresponding products in high yields and regioselectivities. The utility of alkenyl-B(dan) products was proven by their convenient derivatizations.