ELECTRON SPIN RESONANCE OF TRANSIENT ALKYL RADICALS DURING ALKYLLITHIUM-ALKYL HALIDE REACTIONS

Transient alkyl radicals have been observed at room temperature during reactions of several alkyllithium compounds with various alkyl halides in solution. Radical structures and concentrations indicate that the reactions proceed via free-radical mechanisms. The room temperature hyperfine coupling constants of the radicals are discussed. Furthermore, it is suggested that an explanation of nuclear polarization during these and other reactions by the simple mechanism of chemically induced dynamic nuclear polarization derived previously is at least in part, if not generally, inadequate.