MOO2Cl2·2DMSO: Recyclable Catalyst for Selective Oxidation of Alcohols under Solvent Free Conditions

The catalytic activity of the dichlorodioxomolybdenum (MoO2Cl2·2DMSO) complex was investigated for oxidation of aromatic alcohols to corresponding aldehydes using dimethyl sulfoxide (DMSO) as an oxidant under solvent free conditions. The catalyst showed very high conversion and selectivity for aldehyde with high turnover number up to 1000 and high turnover frequency. For substituted benzyl alcohols there was increase in the conversion with electron donating substituents whereas there was decrease in conversion with electron withdrawing substituents. Interestingly though, the catalyst is homogeneous in nature, it was efficiently recycled even up to five recycles without appreciable loss in the activity. Based on the products obtained during reaction the mechanism for oxidation has been proposed.