Hydroformylation reactions in supercritical carbon dioxide using insoluble metal complexes

Abstract

P(OPh)₃, P(OC₆H₄-4-C₉H₁₉)₃ (1) and Ph₂PCH₂CH(CO₂C₁₆H₃₃)CH₂CO₂C₁₆H₃₃ (2) provide rhodium catalysts which are insoluble in scCO₂ but which can show high activity and selectivity in the hydroformylation of hex-1-ene; removing the products from the reaction by flushing them into a second autoclave and decompressing gives the aldehyde product containing undetectable amounts of rhodium and the catalyst can be reused several times.