Simple and efficient copper metal-mediated synthesis of alkoxyamine initiators

Abstract

A simple and efficient method is presented for the preparation of a wide range of alkoxyamines from nitroxide radicals and activated alkyl bromides at room temperature. The reaction requires a stoichiometric amount of copper metal (0.5 mol mol⁻¹ alkyl bromide) and proceeds most rapidly in polar solvents such as acetonitrile, dimethyl sulfoxide or ethanol. No addition of copper(I) or copper(II) salts is necessary. Isolated yields of 71–94% were obtained across a range of alkyl bromide and nitroxide substrates, with reaction times of 1–16 h. The method is compatible with carboxylic acid and amine functionalities.