Synthesis of Secondary and Tertiary Alkylboranes via Formal Hydroboration of Terminal and 1,1-Disubstituted Alkenes

Copper-catalyzed functionalization of terminal or 1,1-disubstituted alkenes with bis­(pinacolato)­diboron and methanol provides formal hydroboration products with exceptional regiocontrol favoring the branched isomer. Pairing this procedure with photocatalytic cross-couplings using iridium and nickel cocatalysis provides an effective, highly regioselective procedure for the hydroarylation of terminal alkenes.