Journal of the American Chemical Society, Vol.141, No.42, 16643-16650, 2019
Generation of Halomethyl Radicals by Halogen Atom Abstraction and Their Addition Reactions with Alkenes
alpha-Aminoradicals undergo halogen atom abstraction to form halomethyl radicals in reactions initiated by the combination of tert-butyl hydroperoxide, aliphatic trialkyl-amine, halocarbon, and copper(I) iodide. The formation of the alpha-aminoradical circumvents preferential hydrogen atom transfer in favor of halogen atom transfer, thereby releasing the halomethyl radical for addition to alkenes. The resulting radical addition products add the tert-butylperoxy group to form alpha-peroxy-beta,beta-dichloropropylbenzene products that are convertible to their corresponding beta,-dichloro-alcohols and to novel pyridine derivatives. Computational analysis clearly explains the deviation from traditional HAT of chloroform and also establishes formal oxidative addition/reductive elimination as the lowest energy pathway.