Carbon Dioxide Induced Phase Switching for Homogeneous‐Catalyst Recycling

Abstract
SwitchPhos: Rhodium complexes formed from PPh3 ligands functionalized with weakly basic amidine groups are highly active catalysts for the hydroformylation of alkenes. On bubbling with CO2 in the presence of water, the yellow rhodium complexes move into the water phase, whereas bubbling with N2 at 60 °C causes them to switch back into the organic phase. The catalysts can be used for reactions in water or an organic phase.