Fluorous biphasic catalysis: A new paradigm for the separation of homogeneous catalysts from their reaction substrates and products

The concept of fluorous biphasic catalysis (FBC) represents a new paradigm for the separation of homogeneous catalysts from their substrates and the p roducts emanating from these reactions. Since its published inception four years ago, FBC has been demonstrated in a variety of catalytic reactions th at encompass hydroformylation, hydrogenation, hydroboration, hydride reduct ion, alkene epoxidation, and alkane and alkene functionalization. The commo n theme in all these homogeneous catalysis reactions, accomplished under FB C conditions, is the modification of the homogeneous catalyst with long-cha in fluoroponytails to render them soluble in the fluorous phase; most hydro phobic substrates, and, to a large extent, hydrophilic products, are relati vely insoluble in fluorocarbon solvents. The fact that fluorocarbon solvent s are apparently nontoxic provides the FBC concept with a possible entry to the new Green Chemistry regime of being environmentally friendly, and ther efore potentially attractive in a wide variety of industrial processes for the catalytic production of important organic chemicals worldwide. Clearly, FBC has caught the imagination of many colleagues all over the world, and thus, the outpouring of new fluorocarbon-soluble catalysts for the aforemen tioned applications will continue unabated into the next millennium.