OXIDATIVE ADDITION AND ISOMERIZATION-REACTIONS - THE SYNTHESIS OF CIS-ARSF4CL AND TRANS-ARSF4CL AND CIS-PHTEF4CL AND TRANS-PHTEF4CL

The stereoselective synthesis and isomerization of cis- and trans-ArSF 4Cl is described, where Ar = Ph, p-MeC6H4, and p-O2NC6H4. Also briefly described is the synthesis of ArSF5, cis- and trans-PhTeF4Cl, and PhT eF5. The oxidative halogenating reagent is a mixture of XeF2 and Cl-, and suitable starting compounds are ArSSAr, ArSF3, and PhTeTePh. Produ cts were characterized by F-19, C-13, and Te-125 NMR spectroscopy, and by the Cl-37/Cl-35 and S-34/S-32 isotope effects on the F-19 NMR chem ical shifts. A mechanism of oxidative halogenation is proposed to acco unt for the stereoselective synthesis of cis- and trans-ArSF4Cl. Ab in itio calculations of optimized geometries of anionic and radical inter mediates, i.e., PhSF3X- and PhSF3X' (X = F, Cl), were carried out with the aid of the GAUSSIAN 92 program.