Two Simple and Highly Efficient Variants of the Griffith‐Ley Oxidation of Alcohols

The Griffith‐Ley oxidation of alcohols to aldehydes and ketones is performed with either RuCl3 ⋅ (H2O)x or a highly stable, well‐defined ruthenium catalyst and with cheap trimethylamine N‐oxide (TMAO) as the oxygen source. The use of n‐heptane as the solvent, which forms a second phase with TMAO and a part of the alcohol, allows the reactions to be performed with a minimum amount of catalyst. This results in high local concentrations and thus to very rapid conversions. Detailed quantum chemical calculations suggest, that the Griffith‐Ley oxidation not necessarily requires high oxidation states of ruthenium but can also proceed with RuII/RuIV species. Ruthenium Catalysis: High yields and selectivities are achieved by using low‐valent ruthenium(II) catalysts for the oxidation of alcohols to carbonyl compounds. DFT calculations give an insight into a possible mechanism.