Cobalt-catalysed hydroformylation of epoxides in the presence of phosphine oxides†
Abstract
A novel cobalt-catalysed hydroformylation of epoxides to β-hydroxyaldehydes was developed. Compared to previous works this methodology proceeds under significantly milder conditions (70 °C; 40 bar of CO/H2 = 1 : 1). Crucial for the activity of the cobalt catalyst is the use of phosphine oxides, especially tricyclohexylphosphine oxide, as cheap and easily available promoters. The hydroformylation reaction can be easily combined with a consecutive one-pot hydrogenation of the in situ generated β-hydroxyaldehydes to produce directly 1,3-diols (important intermediates for polyesters and fibres) starting from epoxides. The rapid formation of a mononuclear acyl cobalt carbonyl complex as an intermediate was observed by in situ FTIR spectroscopy.