Preparation of a novel class of macrocycle and cryptand containing the 1,1′-disubstituted ferrocene unit

Condensation of 1,1′-diacetylferrocene with o-azidobenzaldehyde under appropriate conditions leads either to the [5]-ferrocenophane 2 or the bis(azide) 3, as the only reaction products. Compound 2 undergoes an intramolecular aza-Wittig reaction to give the new type of cryptand 4. Bis(azide) 3 is converted into the macrocycle 5 by a Staudinger reaction with bis(diphenylphosphino)ethane; alternatively, thermally-induced azide decomposition provides the 1,1′-bis(indolyl)ferrocene derivative 6.