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

Diastereoselective Isomerization of ( E

We report herein an unprecedented conversion of β-nitroenones into β-nitro-β,γ-unsaturated ketones. The reaction proceeds under microwave irradiation, furnishing products in good yields and excellent diastereoselectivity. The mechanism of the reaction has been rationalized by means of DFT modelling, which showed that sequential enolization/isomerization steps allowed to break the conjugation of the reagent. The E isomer is preferentially formed thanks to the solvent, which acts catalytically and dictates the regiochemical outcome. Moreover, the obtained β-nitro-β,γ-unsaturated ketones have been efficiently converted into 1,2,5-trisubstituted pyrroles by a one-pot approach. (Figure presented.)