An efficient route to disymmetrically substituted calix[6]arenes. Synthesis of novel ligands presenting a N2S or N3CO2− binding core

The C3v tris-methoxy calix[6]arene was selectively mono-alkylated by dibromoethane yielding a key intermediate for the design of disymmetrically O-substituted calix[6]arenes. Indeed, subsequent reactions with various functional groups afforded novel calix[6]arene-based biomimetic ligands that present a mixed donor N2S or N3CO2− environment in an efficient way.