Combining Homogeneous Reactions and Heterogeneous Separations with Tunable Solvents

Tunable solvents combine the benefits of homogeneous and heterogeneous catalysis while overcoming the limitations of both. Homogeneous mixtures of aprotic organics (such as acetonitrile or dioxane) and polar protic solvents (such as water or polyethylene glycol) are used as reaction media. Facile post-reaction heterogeneous separations are achieved by applying CO2 pressures. We are using the rhodium catalyzed hydroformylation, the palladium catalyzed C-O coupling, and the enzymatic catalyzed hydrolysis of hydrophobic substrates to demonstrate the effectiveness and versatility of tunable solvents. The increased homogeneous reaction rates and the efficient facile heterogeneous separations – about 99.9% in some cases – make tunable solvents an attractive tool for sustainable engineering.