【26th.Sept.】Supramolecular polymers as responsive and chirally amplified platforms for catalysis
日期：2018-09-26
閱讀：892
題目：Supramolecular polymers as responsive and chirally amplified platforms for catalysis
報告人：Dr. Laurent Bouteiller，巴黎六大主任研究員
時間：2018年9月26日上午10:00
地點：化學(xué)樓A樓五樓518報告廳
邀請人：張紹東 特別研究員
內(nèi)容摘要：
Supramolecular polymers are long chains of monomers held by reversible interactions such as hydrogen bonds. The reversibility of the interactions provides potential advantages such as self-repair, stimuli-responsiveness or ease of processing, which makes these systems of high interest for many materials (coatings, gels, elastomers …). In this project, we exploit these features in the field of catalysis.
Hydrogen-bonded supramolecular polymers based on benzene-1,3,5-tricarboxamide (BTA) recognition units [1-3] were investigated as dynamic scaffolds for catalysis. Copolymers were formed by mixing an achiral phosphine-functionalized monomer (the ligand) and a chiral phosphine-free additive (the co-monomer). The aim was to transfer, amplify and switch the supramolecular chirality of the polymer scaffold to intrinsically achiral metal centres located at its periphery. BTA mixtures have been successfully applied in two different asymmetric reactions providing up to 85% and 80% e.e. in the rhodium-catalysed hydrogenation of dimethylitaconate and in the copper-catalysed hydrosilylation of 4’-nitro-acetophenone, respectively. The BTA scaffold supporting the catalytic rhodium or copper centres display strong chirality amplification properties: i) for the rhodium catalysis, the amount of chiral co-monomer can be decreased down to one-fourth of that of the ligand without deteriorating the enantioselectivity of the reaction [4,5] and ii) the chirality of the copper catalyst can be switched during the course of the catalytic reaction [6].?
Overall, our studies reveal the innovative properties of catalysts supported by hydrogen-bonded supramolecular polymers.
參考文獻
[1] A. Desmarchelier, M. Raynal, P. Brocorens, N. Vanthuyne, L. Bouteiller Chem. Commun. 2015, 51, 7397.
[2] A. Desmarchelier, B. Alvarenga, X. Caumes, L. Dubreucq, C. Troufflard, M. Tessier, N. Vanthuyne, J. Ide, T. Maistriaux, D. Beljonne, P. Brocorens, R Lazzaroni, M. Raynal, L. Bouteiller Soft Matter 2016, 12, 7824.
[3] X. Caumes, A. Baldi, G. Gontard, P. Brocorens, R Lazzaroni, N. Vanthuyne, C. Troufflard, M. Raynal, L. Bouteiller Chem. Commun. 2016, 52, 13369.
[4] M. Raynal, F. Portier, P. W. N. M. van Leeuwen, L. Bouteiller J. Am. Chem. Soc. 2013, 135, 17687.
[5] A. Desmarchelier, X. Caumes, M. Raynal, A. Vidal-Ferran, P. W. N. M. van Leeuwen, L. Bouteiller J. Am. Chem. Soc. 2016, 138, 4908.
[6] J. M. Zimbron, X. Caumes, Y. Li, C. M. Thomas, M. Raynal, L. Bouteiller Angew. Chem. 2017, 56, 14016.
