1. International Tomography Center SB RAS, Novosibirsk, Russia;2. N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia;3. Novosibirsk State University, Novosibirsk, Russia;4. Aix Marseille Université, Marseille cedex 20, France
Abstract:
N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐O‐(2‐carboxyprop‐2‐yl) hydroxylamine (BlocBuilder MA) is, among the commercially available alkoxyamines, one of the most efficient for nitroxide‐mediated polymerization (NMP). However, recent results have shown that it does not perform well for the NMP of isoprene. The occurrence of intramolecular hydrogen bonding (IHB) between the carboxylic function and the diethoxyphosphoryl group has been proposed as the reason for its low efficiency. In this article, the presence of this IHB is confirmed using IR, 31P NMR, 31P‐1H HOESY, and DFT calculation results. The solvent effect on this IHB and consequently on kd values is also investigated. However, combining kinetic analysis and rate measurements in various solvents, the influence of this IHB on the C? ON bond homolysis and reformation in alkoxyamine is shown to be very weak.
