Transition metal catalyzed selective B(3)-H or B(4)-H amination of o -carboranes via dehydrogenative BH/NH cross-coupling.

A unique approach to vertex-selective catalytic B-H amination at either the B(3)- or B(4)-position in o -carboranes has been developed. Using different transition metal catalysts, dehydrogenative BH/NH cross-coupling of o -carboranes and free amines has been achieved, leading to a wide variety of cage B(3)- or B(4)-aminated o -carboranes in moderate to high yields with excellent regioselectivity, where carboranyl carboxylic acids and amines can serve as competent coupling partners without any pre-functionalization. The isolation and structural identification of a key intermediate provide an insight into the reaction mechanism in the catalytic B(4)-H amination.