Novel crown ethers by oxidative cycloaddition of thiopheno crown ethers

Abstract

The synthesis of the thiopheno crown ethers 4 is described. The oxidative cycloaddition of these and the known thiopheno crown ethers 2 with N-phenylmaleimide is reported. The resulting sulfoxy-bridged cycloadducts 15 and 16 are transformed oxidatively into the phthalimido crown ethers 14 and 17. An X-ray crystal-structural analysis of the cycloadduct 16b is provided. The complexation behaviour of the crown ethers towards alkali-metal and silver cations is investigated.