Fluorous Biphasic Catalysis: A New Paradigm for the Separation of Homogeneous Catalysts from Their Reaction Substrates and Products

摘要

The concept of fluorous biphasic catalysis (FBC) represents a new paradigm for the separation of homogeneous catalysts from their substrates and the products emanating from these reactions. Since its published inception four years ago, FBC has been demonstrated in a variety of catalytic reactions that encompass hydroformylation, hydrogenation, hydroboration, hydride reduction, alkene epoxidation, and alkane and alkene functionalization. The common theme in all these homogeneous catalysis reactions, accomplished under FBC conditions, is the modification of the homogeneous catalyst with long-chain fluoroponytails to render them soluble in the fluorous phase; most hydrophobic substrates, and, to a large extent, hydrophilic products, are relatively insoluble in fluorocarbon solvents. The fact that fluorocarbon solvents are apparently nontoxic provides the FBC concept with a possible entry to the new Green Chemistry regime of being environmentally friendly, and therefore 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 aforementioned applications will continue unabated into the next millennium.