Synthon-Influential Bond Scission

The generation of active radicals as a result of bond breakage makes cation-radicals useful as syn-thons. For example, arylsulfenamide cation-radicals may be used as sources of sulfenyl radicals. The reaction of 4 -nitrobenzenesulfenanilide with Lewis acids, such as BF3 and AICI3, leads to the formation of sulfonamide cation-radical. The latter appears to be an active sulfenyl transfer species. In the presence of anisol, ethenes, or ethynes, it gives phenylthiyl derivatives (Benati et al. 1990, Gross and Montevecchi 1993). 

Cleavage of carbon-nitrogen bonds is also important in synthetic and, sometimes, biomedical ion-radical chemistry. Thus, triazenes are regarded as carcinogenic compounds. Speiser and Stahl (1992) showed that the benzenediazene cation-radicals easily eliminate -N=N- fragment together with an unpaired electron. 

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