Phase transfer catalysis or interfacial catalysis is a syn thetic technique involving transport of an organic or inorganic salt from a solid or aqueous phase into an organic liquid where reaction with an organic-soluble substrate takes place. Over the past 15 years there has been an enormous amount of effort invested in the development of this technique in organic synthe sis. Several books and numerous review articles have appeared summarizing applications in which low molecular weight catalysts are employed. These generally include either crown ethers or onium salts of various kinds. While...