Single Electron Transfer in the Reaction of Enolates with Alkyl Halides

Article abstract of DOI:10.1021/jo00218a007

Single electron transfer (SET) in the reaction of a model system consisting of lithiopropiophenone with primary neopentyl type alkyl halides and tosylate was investigated by (1) the use of an appropriate cyclizable alkyl radical probe, (2) observing the effect of varying the leaving group on reaction rate and product distribution, (3) studying the effect of light, di-tert-butyl nitroxyl radical, and p-dinitrobenzene on the rate of reaction, (4) observing the consequence of varying solvent composition on both the reaction rate and product distribution, and (5) studying the effects of the radical traps, dicyclohexylphosphine and 1,4-cyclohexadiene, on product composition.The results of these studies indicate that single electron transfer is the major reaction pathway involved in the reaction of the enolate with the alkyl iodide in HMPA and that the corresponding bromide and tosylate react by an S_N2 process.