OXIDATIVE FLUORINATION IN THE PH(2)SO-XEF2-CL- SYSTEM AND FLUORINE EXCHANGE IN THE PH(2)S(O)F-2-PH(2)S(O)F+ SYSTEM

Oxidative fluorination of diphenyl sulfoxide with xenon difluoride occ urs under mild conditions in the presence of chloride ion to give Ph(2 )S(O)F-2 in quantitative yield. Chloride ion appears to react with xen on difluoride to generate fluoride ion, and a mechanism of oxidative f luorination is proposed that involves anionic Ph(2)S(OF- and radical P h(2)S(O)F-. intermediates. Addition of cationic Ph(2)S(OF+ to Ph(2)S(O )F-2 initiates rapid fluorine exchange, presumably via a symmetrical f luorine-bridged intermediate, and this exchange process was monitored by C-13 and F-19 NMR spectroscopy. In the presence oi chloride ion, Ph (2)S(O)Cl-2 is formed and can be identified by C-13 NMR and by its hyd rolysis to Ph(2)SO(2). Mechanisms are proposed for these reactions, an d ab initio molecular orbital calculations (GAUSSIAN92) were carried o ut of the postulated intermediates.