title: Cyclopeptoids: a novel class of phase-transfer catalysts.
abstract: The synthesis, complexation properties and catalytic activities under phase-transfer (PT) conditions of differently substituted cyclohexapeptoids are reported. Association constants, for small cationic alkali, and catalytic performances, in a model nucleophilic substitution, are comparable to those of representative crown ethers. Noteworthy, the N-[2-(2-methoxyethoxy)ethyl] side chain derivative presents a catalytic efficiency comparable to that of crypt-222, and higher than some commonly used quaternary ammonium salts and crown ethers. Moreover its association constant for Na(+) complexation proved to be higher when compared with dicyclohexyl-18-crown-6. The synthesized cyclohexapeptoids represent the first example of these peptidomimetics in PT catalysis, anticipating interesting applications in biphasic PT methodology.
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy. gdsala@unisa.it
authors.forename: Giorgio
authors.initials: G
authors.lastname: Della Sala
authors.forename: Brunello
authors.initials: B
authors.lastname: Nardone
authors.forename: Francesco
authors.initials: F
authors.lastname: De Riccardis
authors.forename: Irene
authors.initials: I
authors.lastname: Izzo
mesh_terms: D002384:Catalysis; D002414:Cations, Monovalent / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D043844:Crown Ethers / Q000737:chemistry; D008672:Metals, Alkali / Q000737:chemistry*; D034444:Peptoids / Q000737:chemistry*; D044367:Phase Transition; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012964:Sodium / Q000737:chemistry
chemical_list: D002414:Cations, Monovalent; D056831:Coordination Complexes; D043844:Crown Ethers; D008672:Metals, Alkali; D034444:Peptoids; D000644:Quaternary Ammonium Compounds; C002570:dicyclohexyl-18-crown-6; D012964:Sodium