Divergent Synthesis of Alcohols and Ketones via Cross-Coupling of Secondary Alcohols under Manganese Catalysis

A homogeneous manganese-catalyzed cross-coupling of two secondary alcohols for the divergent synthesis of gamma-disubstituted alcohols and beta-disubstituted ketones is reported. Employing the well-defined Mn-MACHO(Ph) as the catalyst, this novel protocol has a broad substrate scope with good functional group tolerance and affords a diverse library of valuable disubstituted alcohols and ketones in moderate to good yields. The strong influence of the reaction temperature on the selective formation of alcohol products was theorized in preliminary DFT studies. Studies have shown that the Gibbs free energy of the formation of alcohols is thermodynamically more favourable than corresponding ketones at a lower temperature.