Kinetic studies on the formation and decay of some sulfonium radicals

Sulphonylium ions in the gas phase

“…The similarity of the bond dissociation energies for alkane-and arenesulphonyl chlorides was not unexpected since the corresponding sulphonyl radicals have been shown by EPR spectroscopy to be CT radicals and, therefore, there can be little or no delocalization of the unpaired electron even when there is a neighboring aromatic ring. [30][31][32] Moreover, the present results are in good agreement with the early estimates of -297 kJ mol-' for the bond dissociation energies of alkanesulphonyl chlorides3 and in contrast with the suggested stabilization energy of 54 kJ mol-' for the benzenesulphonyl radical.34…”

Iron-catalyzed sulfonyl radical formations from sulfonylhydrazides and oxidative addition to alkenes

“…It is presumed this low yield was caused by competitive desulfonation of the resultant sulfonyl radical to generate a relatively stable cyclohexyl radical. 12 In support of this presumption, the reaction of noctylsulfonylhydrazide (2h), which is expected to give a less stable normal alkyl radical by desulfonation, gave corresponding bhydroxysulfone compound 3h in good yield (Entry 8). Finally, the scope of alkenes in the present reaction was examined (Table 3).…”

Photocatalytic Radical Alkylation of Electrophilic Olefins by Benzylic and Alkylic Zinc-Sulfinates

“…Although the SO 2 moiety is preserved with eosin, in our conditions zinc sulfinates enable the alkylation of Michael acceptors. Organosulfone mediated radical alkylation and vinylation reactions were developed by Zard and are centered on the facile decomposition of alkylsulfone radicals to give alkyl radical with the liberation of sulfur dioxide . This desulfonylation is reversible, and the equilibrium is shifted if the radical is stabilized, as in our case .…”

“…Lately, oxidative conditions were applied to the generation of radical species starting from sulfinates, taking advantage of the fact that oxidation potentials of sulfinates are lower compared to other precursors of radicals, such as carboxylates . Extrusion of SO 2 induced by oxidative conditions generates the corresponding aryl or alkyl radical . Recently, a radical-based functionalization strategy that involves the use of sodium and zinc bis­(alkylsulfinate) reagents has been developed by Baran (Scheme ).…”