Copper-Catalyzed Reagent-Controlled Regioselective Cyanoborylation of Vinylarenes.

A copper-catalyzed borylation/benzylic cyanation of vinylarenes whose regioselectivity is seemly common but scarcely achieved is reported. This unprecedented regioselectivity is realized through a structure-distinctive cyanating reagent, dimethylmalononitrile. This reaction can be applied to both π-extended and simple vinylarenes with various diboron reagents, and it exhibits good functional group compatibility. With the ample transformations of cyano and boronate groups, this reaction provides expedient access to complex organic structures.