Alicyclophanes: a new range of cyclophanes containing rigid alicyclic subunits in place of the aromatic rings

Norbornenosuccinimides have been coupled stereoselectively with 2,5-bis(trifluoromethyl-1,3,4-oxadiazole to prepare alicyclic scaffolds 5 and 20. Alkylations of the terminal succinimido-nitrogens of 5 with bis-alkylating agents have produced macrocyclic compounds in a short, high-yielding procedure. Alicyclophanes containing one scaffold subunit were obtained from 1,6-dibromohexane, 1,5-dichloro-3-oxapentane, 1,11-dibromo-3,6,9-trioxaundecane and 9,10-bis(chloromethyl)anthracene. Larger alicyclophanes incorporating two spacer subunits were formed by intermolecular cyclisation of 5 with 1,2-dibromoethane or 19 with m- or p-xylylene dibromide. Reaction of 5 with propargyl bromide, followed by oxidative coupling (CuCl) of the pendant acetylenes provided bis-acetylenic alicyclophane 13.