Synthesis of Cavity Extended Cyclotriveratrylenes

Aromatic nucleophilic substitution reaction of cyclotriguaiacylene 1 with fluorobenzene derivatives bearing electron-withdrawing groups X (CHO, COCH3, CN, NO2) in the para position gives a series of cyclotriveratrylene derivatives (3a-d), where the X substituents can be transformed to hydrogen-bond donor groups to afford new CTV-based heteroditopic receptors. The substituents of compounds 3a-d favor the facile demethylation reaction of the CTV derivatives. Attempts to perform alkylation reactions on derivatives (8c,d) evidenced the formation of a stereoisomeric mixture of symmetrical and unsymmetrical compounds.