The kinetics of methanolysis of a number of esters endowed with a carboxylate anchoring group have been investigated in the presence of di- and trinuclear Zn2+ complexes of calix[4]arenes functionalized at the upper rim with nitrogen ligands. The results (i) emphasize the importance of a good match between ester size and intermetal distance, (ii) reveal a substrate independent superiority of the 1,2-vicinal dinuclear catalyst 1-Zn2 to its 1,3-distal regioisomer 2-Zn2, and (iii) provide further evidence for the concurrence of the three metal ions of 3-Zn3 in the catalytic mechanism.
Calix[4]arene-based Zn2+ complexes as shape- and size-selective catalysts of ester cleavage / Cacciapaglia, R; Casnati, A; Mandolini, Luigi; Reinhoudt, Dn; Salvio, Riccardo; Sartori, A; Ungaro, R.. - In: JOURNAL OF ORGANIC CHEMISTRY. - ISSN 0022-3263. - STAMPA. - 70:(2005), pp. 5398-5402. [10.1021/jo050196r]
Calix[4]arene-based Zn2+ complexes as shape- and size-selective catalysts of ester cleavage
MANDOLINI, Luigi;SALVIO, RICCARDO;
2005
Abstract
The kinetics of methanolysis of a number of esters endowed with a carboxylate anchoring group have been investigated in the presence of di- and trinuclear Zn2+ complexes of calix[4]arenes functionalized at the upper rim with nitrogen ligands. The results (i) emphasize the importance of a good match between ester size and intermetal distance, (ii) reveal a substrate independent superiority of the 1,2-vicinal dinuclear catalyst 1-Zn2 to its 1,3-distal regioisomer 2-Zn2, and (iii) provide further evidence for the concurrence of the three metal ions of 3-Zn3 in the catalytic mechanism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
