Selective Formation of 2-Phenylethanol in the Homologation of Benzyl Alcohol

Article abstract of DOI:10.1246/bcsj.59.2565

High selectivity of 2-phenylethanol (87percent) in the homologation of benzyl alcohol was obtained with cobalt-ruthenium mixed catalyst.The formation of toluene as the major by-product was suppressed by adding water at low reaction temperature.Bromide as promoter was more effective for the homologation than chloride or iodide.From in situ IR observation, ^-, which was active species for the homologation, was found to be produced by the dissociation of but not by the disproportionation of under the reaction temperature employed (120 deg C).It was also revealed that ruthenium chloride as precatalyst was converted into a bromocarbonyl complex of ruthenium under the homologation conditions.