Regioselective O-substitution of p-tert-butylcalix[7]arene

Marco Martino; Luisa Gregoli; Carmine Gaeta; Placido Neri

doi:10.1021/ol025755k

Regioselective O-substitution of p-tert-butylcalix[7]arene

Org Lett. 2002 May 2;4(9):1531-4. doi: 10.1021/ol025755k.

Authors

Marco Martino¹, Luisa Gregoli, Carmine Gaeta, Placido Neri

Affiliation

¹ Dipartimento di Chimica, Università di Salerno, Via S. Allende 43, I-84081 Baronissi, SA, Italy.

PMID: 11975621
DOI: 10.1021/ol025755k

Abstract

[structure: see text]. The first examples of selectively functionalized calix[7]arenes have been obtained by weak-base promoted O-alkylation or O-benzoylation of p-tert-butylcalix[7]arene. Mono-, 1,3- and 1,4-disubstituted calix[7]arenes have been obtained in workable yields, while the 1,2,4,6-tetrasubstitution was achieved with surprisingly high selectivity (50-88% yield) by using K2CO3 as base. A rationale for this finding is proposed.