New and improved routes to alkoxyamine initiators for controlled radical polymerisation

Abstract

O-substituted hydroxylamines were synthesized in almost quantitative yields using ultrasound and Mn(OAc)3 (in substance or regenerated in situ by an oxidizing agent) as electron-transfer agent. Two novel synthetic methods for the synthesis of alkoxyamines from organic halides and stable nitroxide radicals are introduced. One of them utilises cyancobalamine (vitamine B12), the other SmI2 as catalyst and magnesium metal as reductive agent. The yields are good for the first method and excellent for the second. The initiators were tested in controlled radical polymerisation of styrene, methylmethacrylate and 4-vinylpyridine.