Construction of anomalously bent biphenyl structure using conformational properties of calix[4]amide

Abstract

C 2 v -symmetrical cyclic tetramers of aromatic amides were simply synthesized in moderate yield by condensation reaction of N, N′-dimethyl-1,3-phenylenediamine and isophthalic acid derivatives using dichlorotriphenylphosphorane. The calix[4]amides exist in 1,3-alternate structure with cis conformation of tertiary aromatic amides, which were shown to be a versatile scaffold leading to a bowl-shaped macrocyclic compound possessing a anomalously strained structure, a bent hinge angle between two aromatic ring planes of biphenyl moiety, via an intramolecular ligation reaction.