Cobalt-Catalyzed, N-H Imine-Directed Hydroarylation of Styrenes.

A cobalt-catalyzed, N-H imine-directed hydroarylation reaction of styrenes is reported. A variety of diaryl and aryl alkyl N-H imines participated in the reaction to afford the corresponding branched adducts in good yield and regioselectivity. Interestingly, unsymmetrical diaryl imines with modest electronic biases reacted regioselectively at one of the aryl rings. Furthermore, the branched selectivity was reversed for substrates bearing a secondary directing group or a bulky pivaloyl N-H imine.