Copper-Catalyzed Regioselective Silaboration of Aryl Allenes

We report a copper-catalyzed silaboration of aryl-substituted terminal allenes with a silylborane reagent (PhMe₂Si-Bpin) that furnishes silyl-substituted allylboronates with good regio- and stereoselectivity under mild conditions. A range of aryl allenes bearing electron-donating or electron-withdrawing groups afforded the corresponding allylboronate products in good to excellent yields (up to 97%) with high regio- and stereocontrol. This method expands copper-catalyzed silaboration of terminal allenes from alkyl-substituted to aryl-substituted substrates.