Single Electron Delivery to Lewis Pairs: An Avenue to Anions by Small Molecule Activation.

Single electron transfer (SET) reactions are effected by the combination of a Lewis acid (e.g., E(CF) E = B or Al) with a small molecule substrate and decamethylferrocene (CpFe). Initially, the corresponding reactions of (PhS) and (PhTe) were shown to give the species [CpFe][PhSB(CF)] 1 and [CpFe][(μ-PhS)(Al(CF))] 2 and [CpFe][(μ-PhTe)(Al(CF))] 3, respectively. Analogous reactions with di-tert-butyl peroxide yielded [CpFe][(μ-HO)(B(CF))] 4 with isobutene while with benzoyl peroxide afforded [CpFe][PhC(O)OE(CF)] (E = B 5, Al 6). Evidence for a radical pathway was provided by the reaction of PhSnH and p-quinone afforded [CpFe][HB(CF)] 7 and [CpFe][(μ-OCH)(E(CF))] (E = B 8, Al 9). In addition, the reaction of TEMPO with Lewis acid and CpFe afforded [CpFe][(CHMeNOE(CF)] (E = B 10, Al 11). Finally, reactions with O, Se, Te and S gave [CpFe][((CF)Al(μ-O)Al(CF))] 12, [CpFe][((CF)Al(μ-Se)Al(CF))] 13, [CpFe][(μ-Te)(Al(CF))] 14 and [CpFe][(μ-S)B(CF))] 15, respectively. The mechanisms of these SET reactions are discussed, and the ramifications are considered.