Synthetic scope of alcohol transfer dehydrogenation catalyzed by Cu/Al2O3: a new metallic catalyst with unusual selectivity.

A method for the anaerobic oxidation of a wide series of alcohols including cyclohexanols and steroidal alcohols, has been set up. It relies on a transfer dehydrogenation reaction from the substrate alcohol to styrene catalyzed by a heterogeneous, reusable copper catalyst under very mild liquid-phase experimental conditions (90 degrees C, N(2)) and shows unusual selectivity. Thus, the method is selective for the oxidation of secondary and allylic alcohols even in the presence of unprotected primary and benzylic alcohols. Electronic effects and the choice of the hydrogen acceptor account for the selectivity observed.

Anaerobic oxidation of non-activated secondary alcohols over Cu/Al2O3.

A liquid phase, transfer dehydrogenation reaction promoted by an 8% Cu/Al(2)O(3) catalyst allows complete conversion of secondary alcohols into ketones under very mild conditions and in short times without any additives.