Copper/Bisphosphine Catalysts in the Internally Borylative Aminoboration of Unactivated Terminal Alkenes with Bis(pinacolato)diboron.

Abstract

Cu(I)/modified dppbz catalyst systems for the regioselective aminoboration of unactivated terminal alkenes have been developed. The bisphosphine-based Cu catalysis enables the introduction of the readily transformable Bpin group at the more congested internal position and shows better regioselectivity for broader terminal alkenes involving sterically demanding allylbenzenes, which are relatively challenging substrates in the previous IPrCuBr catalysis. Additionally, the second-generation catalyst systems accommodate the exo-methylene-type disubstituted alkenes to deliver the corresponding aminoborated products in good yields with a high regioselectivity.