At elevated temperatures, nitroxides (e.g. 1,1,3,3-tetramethyl-2,3- dihydroisoindol-2-yloxyl) undergo a slow addition reaction with acrylonitrile, methyl acrylate and styrene to give the bis-nitroxide adducts. With alkenes containing an allylic hydrogen such as methyl methacrylate and 6-methylene-1,4-oxathiepan-7-one, the major reaction observed was hydrogen abstraction. The resulting hydroxylamines can be trapped as Michael addition products. (C) 2000 Elsevier Science Ltd.
- Radical trapping