Halides triphenyltin radical

CV studies indicate that Ph3SnY, where Y = Cl, OTf, OCHO, SnPh3, do not serve as a source of the triphenyltin radical because in these instances the radical is generated at potentials where it is either oxidized or reduced [19]. Reaction of the triphenyltin radical with an alkyl halide or a disulfide produces a carbon- or a sulfur-centered radical, respectively. Use of the latter transformation in conjunction with a subsequent intramolecular cyclization onto an alkene is nicely illustrated by the conversion of /6-lactam 62 to the cephalosporin analog 63. 

Selenides are also nucleophilic and produce isolable selenonium salts (9) when treated with alkyl halides. They are easily oxidized to selenoxides (10) and further to selenones (11) under more forcing conditions (see Section 4). Reduction of selenides to the corresponding hydrocarbons is most conveniently achieved with nickel boride,or with tri-n-butyl- or triphenyltin hydride under radical conditions. " Other reagents for reductive deselenization include Raney nickel, lithium triethylborohydride, and lithium in ethylamine (Scheme 4). Benzylic selenides undergo radical extrusion reactions under thermal or photolytic conditions to produce... 

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