There is increasing interest in the chemistry of sulphonium salts having a tricoordina- tion sulphur atom attached to three carbon atoms, where the substituents may be alkyl, cycIoalkyl, alkynyl, aryl or heteroaryl groups, or where the sulphur atom is part of a monocycIic or bicycIic system. Sulphonium salts become increasingly useful and important in organic synthesis since the demonstration in 1962 by Corey and Chaykovskyl of the easy preparation and highly ...