Molybdenum/Quinone-Catalyzed Deoxygenative Coupling of Aromatic Carbonyl Compounds

A catalytic amount of Mo(CO)6 and an ortho-quinone ligand, in the presence of triphenylphosphine as a mild reductant enables the intermolecular reductive coupling of aromatic aldehydes and the intramolecular cou-pling of aromatic ketones to produce functionalized alkenes. Diaryl- and diheteroaryl alkenes are synthesized typically with high (E)-selectivity and with a tolerance of bromide, iodide, and steric hindrance. Intramolecular coupling of 1,6-diketones under similar conditions affords 9,10-disubstituted phenanthrenes.