Catalytic Hydrogenolysis of Aryl C-F Bonds Using a Bimetallic Rhodium-Indium Complex

A homogeneous rhodium-indium catalyst hydrodefluorinates substrates bearing strong aryl C-F bonds, including difluoro- and fluorobenzene, using 1 atm of H-2, alkoxide bases, and moderate temperatures (70-90 degrees C). Characterization of catalytic intermediates establishes a formal Rh-I/Rh-I redox cycle. The Rh -> In interaction is proposed to enable catalysis by stabilizing the reactive Rh--(I) species, which is responsible for cleaving the Ar-F bond and is ultimately regenerated using H-2 and base.