Centro CNR and Dipartimento di Chimica Organica e Industriale dell' Università , Via Golgi 19, 1-20133, Milano, Italy
Abstract:
Abstract The ability of macrocyclic polyethers to activate enolates has been studied in the alkylation of deoxybenzoin (1) with butyl derivatives nBuY (Y = Br, I, OMes) catalyzed by crown ether PHDB18C6 (7) or cryptand [2.2.2, C10] (8) under phase-transfer catalysis (PTC) and homogeneous (chlorobenzene) conditions. The enolate reactivity is mainly determined by the ligand (cryptand>crown ether) and solvent (increasing with the polarity, in the order: toluene