Oxidative esterification of aldehydes with alcohols using imidazolium perrhenate catalysts

Four imidazolium perrhenates were synthesized, characterized and used as efficient catalysts for the oxidative esterification of benzaldehydes with alcohols. The perrhenates showed high catalytic activity toward oxidative esterifications, whereas good yields could be obtained for a series of aldehyde and alcohol substrates. The results indicate that the steric effects of functional groups on the aromatic ring play important roles in the formation of esters. Moreover, the alkyl structures of the alcohols also dramatically affect the product yields.