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.
Cyclopeptoids: a novel class of phase-transfer catalysts
DELLA SALA, Giorgio;NARDONE, BRUNELLO;DE RICCARDIS, Francesco;IZZO, Irene
2013-01-01
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
