A ruthenium-catalyzed one-pot method for α-alkylation of ketones with aldehydes

Ketones react with an array of aldehydes in dioxane at 80 °C in the presence of a catalytic amount of RuCl2(PPh3)3 along with KOH to give the corresponding α-alkylated ketones in moderate to good yields. A reaction pathway involving base-catalyzed cross-aldol reaction between ketones and aldehydes to form α,β-unsaturated ketones and regioselective reduction of carbon–carbon double bond of α,β-unsaturated ketones is proposed for this catalytic process.

Ketones undergo α-alkylation with aromatic and aliphatic aldehydes in dioxane at 80 °C in the presence of a catalytic amount of RuCl2(PPh3)3 together with KOH. The reaction is applicable to aryl(methyl), alkyl(methyl), and benzo-fused cyclic ketones, and in the case of alkyl(methyl) ketones the alkylation takes place exclusively at less-hindered methyl position over α-methylene and -methine.Figure optionsDownload as PowerPoint slide