Cobalt‐Mediated Radical Coupling (CMRC): An Unusual Route to Midchain‐Functionalized Symmetrical Macromolecules |
| |
| Authors: | Antoine Debuigne Dr Rinaldo Poli Prof Julien De Winter Pascal Laurent Dr Pascal Gerbaux Prof Philippe Dubois Prof Jean‐Paul Wathelet Prof Christine Jérôme Prof Christophe Detrembleur Dr |
| |
| Institution: | 1. Center for Education and Research on Macromolecules, University of Liège, Sart‐Tilman, B6a, 4000 Liège (Belgium), Fax: (+32)?4‐366‐3497;2. Laboratoire de Chimie de Coordination, University of Toulouse, UPS, INPT, 205, route de Narbonne, 31077 Toulouse (France);3. Institut Universitaire de France, 103, bd Saint‐Michel, 75005 Paris (France);4. Mass Spectrometry Center, Organic Chemistry Laboratory, University of Mons, 20, Place du Parc, 7000 Mons (Belgium);5. Unit of General and Organic Chemistry, Gembloux Agricultural University (FUSAGx), 2, Passage des déportés, 5030 Gembloux (Belgium);6. Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons, 23, Place du Parc, 7000 Mons (Belgium) |
| |
| Abstract: | Cobalt‐mediated radical coupling (CMRC) is a straightforward approach to the synthesis of symmetrical macromolecules that relies on the addition of 1,3‐diene compounds onto polymer precursors preformed by cobalt‐mediated radical polymerization (CMRP). Mechanistic features that make this process so efficient for radical polymer coupling are reported here. The mechanism was established on the basis of NMR spectroscopy and MALDI‐MS analyses of the coupling product and corroborated by DFT calculations. A key feature of CMRC is the preferential insertion of two diene units in the middle of the chain of the coupling product mainly according to a trans‐1,4‐addition pathway. The large tolerance of CMRC towards the diene structure is demonstrated and the impact of this new coupling method on macromolecular engineering is discussed, especially for midchain functionalization of polymers. It is worth noting that the interest in CMRC goes beyond the field of polymer chemistry, since it constitutes a novel carbon–carbon bond formation method that could be applied to small organic molecules. |
| |
| Keywords: | cobalt dienes poly(acrylonitrile)s polymerization radical reactions |
|
|
