Chemodivergent coupling of azoarenes with benzyl alcohols via a borrowing hydrogen strategy using a well-defined nickel catalyst

Abstract

Chemodivergent (de)hydrogenative coupling of azoarenes with benzyl alcohols is achieved via the NN bond activation using an inexpensive and well-defined (6-OH-bpy)NiCl₂ catalyst. This protocol highlights the construction of C–N bonds via a borrowing hydrogen strategy that offers substituted imines and amines. A range of azo compounds couple with various substituted benzyl alcohols in a tandem hydrogenation/dehydrogenation process. The nickel catalyst along with the K₂CO₃ or KO^tBu base governed the selectivity in imine and amine formation. A preliminary mechanistic study establishes the crucial role of metal–ligand cooperation (MLC) comprising the distinct radical pathways.