The synthesis of propanol from ethylene over homogeneous Rh/amine catalytic system via auto-tandem reductive hydroformylation

Here we report our investigation on auto-tandem reductive hydroformylation of ethylene, which allows to obtain propanol in a single technological step. The effect of pressure, ligand structure, temperature, solvent type, ratio of components, and gas supply on the process was studied. It was found that ethylene could be successfully converted to propanol by reductive hydroformylation on a homogeneous Rh/NR3 catalytic system with productivity per Rh atom up to 1299 h-1 (9.0 MPa, 110 celcius). Under milder conditions, low ethylene concentrations and constant syngas supply should be applied. Noteworthy, by using atmospheric distillation as a separation procedure, the system can be used for multiple consecutive reactions without significant activity loss. Probable pathways for the formation of active species and the transformation of rhodium complexes during the distillation process are discussed.