Alternative pathways in the ruthenium catalysed hydrogenation of CO to alcohols

Abstract

CO hydrogenation in [PBu₄]Br in the presence of [Ru₃(CO)₁₂] gives predominantly methanol, ethanol and propanol with small amounts of 1,2-ethanediol. Using RuO₂ as the catalyst precursor, the same products are formed along with higher alcohols (1-butanol –1-heptanol). Reactions carried out using added ¹³CH₃OH or ¹³CO show that ethanol and propanol come from homologation reactions of methanol and ethanol respectively, but that the higher alcohols are not formed through the lower alcohols as intermediates.