Regioselective O-substitution of p-tert-butylcalix[7]arene.
[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.
Martino
Marco
M
Dipartimento di Chimica, Università di Salerno, Via S. Allende 43, I-84081 Baronissi, SA, Italy.
Gregoli
Luisa
L
Gaeta
Carmine
C
Neri
Placido
P