Oxidative dimerization of primary alcohols with 2-butanone in the presence of an amino alcohol-based Ir bifunctional catalyst was accomplished for the first time. The reaction proceeds with 1-2 mol% of the catalyst and 0.3 mol equivalents of K2CO3 in 2-butanone at room temperature to give the corresponding dimeric esters in 30-93% yield.
2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) catalyzes the direct oxidation of primary alkyl alcohols to symmetric esters at 1-2 mol% loadings. These rapid reactions take place at room temperature to afford the products in yields of 55-99%.