Lower rim arylation of calix[n]arenes with extended perfluorinated domains

Exhaustive O-arylation of p-tert-butylcalix[n]arenes 2 (n = 4-8) with an excess of 3-pentadecafluoroheptyl-5-pentafluorophenyl-1,2,4-oxadiazole 3 and K2CO3 in refluxing acetonitrile provides an easy entry to a new family of perfluorinated calix[n]arenes 1. The cyclic tetramer furnishes a mixture of cone, partial cone, and 1,2-alternate conformers, while the larger macrocycles afford single products. The structures of all new compounds are substantiated by NMR techniques and MALDI-TOF mass spectral data. Single-crystal X-ray diffraction studies on the pentamer derivative 1b reveal a distorted cone-in conformation of the calixarene cup.