Synthesis and novel reactivity of halomethyldimethylsulfonium salts

Iodomethyl-, chloromethyl-, and fluoromethyldimethylsulfonium salts, 4b-d, have been synthesized and are observed to be highly reactive molecules that exhibit extraordinary diversity with respect to the nature of their reacti vity, undergoing facile direct substitution (S(N)2) reactions, but also bei ng highly susceptible to electron-transfer reactions. Cyclic voltametry exp eriments indicated that the iodomethyldimethylsulfonium compound, 4b, is a potent electron acceptor, even surpassing the reactivity of perfluoro-n-alk yl iodides in that capacity. The iodo- and chloromethyldimethylsulfonium sa lts, 4b,c, as well as the analogous iodomethyltrimethylammonium salt, 3a, a re shown to be reactive SET accepters.