The triphasic transfer hydrogenation of aromatic aldehydes by aqueous sodium formate in the presence of heterogenized ruthenium(II) complexes bound to swellable polymer matrices

Aromatic aldehydes can be reduced to the corresponding alcohols by hydrogen transfer from HCO2Na in the presence of Ru(II) complexes bound to swellable polymer matrices and a quaternary ammonium salt. The reaction kinetics have been measured between 50 and 80 °C. The process was shown to depend on the structure of the aldehyde acceptor, on the concentrations of formate donor and phase-transfer agent, on the amount of the catalyst and also to be sensitive to the polarity of the organic solvent. The observed activation energy, Ea = 20.80 kcal mol−1, suggests that process is a predominantly chemically controlled reaction. A general reaction mechanism and rate equation have been proposed.

Aromatic aldehydes can be reduced to the corresponding alcohols by hydrogen transfer from HCO2Na in the presence of Ru(II) complexes bound to swellable polymer matrices and a quaternary ammonium salt. The reaction kinetics have been measured between 50 and 80 °C. The process was shown to depend on the structure of the aldehyde acceptor, on the concentrations of formate donor and phase-transfer agent, on the amount of the catalyst and also to be sensitive to the polarity of the organic solvent. The observed activation energy, Ea = 20.80 kcal mol−1, suggests that process is a predominantly chemically controlled reaction. A general reaction mechanism and rate equation have been proposed.Figure optionsDownload as PowerPoint slide