Photochemical hydroformylation of olefins with rhodium catalysts at elevated pressure

Abstract The catalytic activity of RhCl 3 and RhHCO(PPh 3 ) 3 towards hydroformylation, hydrogenation and isomerization of olefins such as 1-octene, styrene, 1,5- and 2,4-hexadiene is enhanced by UV-irradiation. The most active photocatalytic system consists of RhCl 3 and norbornadiene, which catalyses the hydroformylation of 1-octene even at room temperature. The photochemical reaction of norbornadiene itself at 80 bar CO/H 2 and 20 °C lead to a copolymer between norbornadiene and carbon monoxide, in contrast to the thermal reaction at 80 bar CO/H 2 and 80 °C which results in the formation of mono- and dialdehydes. A UV-autoclave allowing photochemical reactions at pressures up to 300 bar is described.