ansa-Ferrocene-Incorporated Calixpyrroles and Calixphyrins: Syntheses and Spectral/Structural Characterization

The syntheses and spectral/structural characterization of ansa-ferrocene-incorporated normal calixphyrins and core-modified calixpyrroles and calixphyrins are reported. Acid-promoted dehydrative condensation of 1,1′-bis(dimethylpyrrolylmethyl)ferrocene and 2,5-bis(dimethylhydroxymethyl)thiophene/furan yielded ansa-ferrocene-based core-modified calixpyrroles, while acid-catalyzed dehydrative condensation of 1,1′-bis(diphenylpyrrolylmethyl)ferrocene with the aryl aldehydes and 2,5-bis(phenylhydroxymethyl)thiophene followed by DDQ oxidation resulted in the formation of ansa-ferrocene-appended normal and core-modified calixphyrins, respectively. The newly synthesized macrocycles were characterized by FAB-MS, NMR, and UV–vis spectral analyses and finally confirmed by single-crystal X-ray structural analysis. All these studies clearly revealed the introduction of ferrocene in the main framework of the corresponding macrocycles in an ansa-type way. The core-modified calixpyrroles adopt a 1,3-alternate conformati...