Mechanism of the hydrogenolysis of ethers over silica-supported rhodium catalyst modified with rhenium oxide

The Rh–ReOx/SiO2 (Re/Rh = 0.5) exhibited high activity in the hydrogenolysis of ethers with an OH group. The CO bond neighboring CH2OH group was selectively dissociated: The hydrogenolysis of tetrahydro-5-methyl-2-furfuryl alcohol and 2-isopropoxyethannol gave 1,5-hexanediol and ethanol + isopropanol, respectively. This tendency suggests the regioselective CO dissociation mechanism via anion intermediate formed by the attack of hydride and the subsequent protonation of the anion.