文献类型：期刊文献

英文题名：Dynamic Covalent Metathesis in the C=C/C=N Exchange between Knoevenagel Compounds and Imines

作者：Gu, Ruirui[1,2];Flidrova, Karolina[1];Lehn, Jean-Marie[1]

机构：[1]Univ Strasbourg, Lab Chim Supramol, Inst Sci Ingn Supramol, 8 Allee Gaspard Monge, F-67000 Strasbourg, France;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2018

卷号：140

期号：16

起止页码：5560

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20181805114726);WOS:【SCI-EXPANDED(收录号:WOS:000431095100031)】；

基金：We thank Dr. Jean-Louis Schmitt for discussions of the NMR and mass spectral data. We thank in particular one of the referees for detailed comments. We also thank the ERC (Advanced Research Grant SUPRADAPT 290585), the ANR DYNAFUN grant no. ANR-15-CE29-0009-01, the USIAS, and the University of Strasbourg for financial support. R.G. gratefully acknowledges a doctoral scholarship from the China Scholarship Council. K.F. thanks the ERC for postdoctoral fellowship support. We also thank Wende Hu (Shanghai) for the computational results. Dedicated to Professor Dieter Seebach.

语种：英文

外文关键词：Reaction intermediates - Mass spectrometry

摘要：Fast and reversible dynamic covalent C=C/C=N exchange takes place without catalyst in nonpolar solvents between barbiturate-derived Knoevenagel (Kn) compounds and imines. A detailed study of the reaction indicates that it proceeds by an associative organo-metathesis mechanism involving the formation of a four-membered ring azetidine intermediate by addition of the imine C=N group to the C=C bond of the Kn compound. This intermediate could be generated cleanly and stabilized at low temperature by condensation of the o,p-dinitrophenyl Kn derivative with the cyclic imine 1-azacyclohexene. It was characterized by extensive NMR and mass spectrometric studies. The process described represents a genuine dynamic covalent organo-metathesis through a four-membered ring adduct as intermediate. It paves the way for the exploration of a wide set of dynamic systems involving (strongly) polarized C=C bonds and various imines, extending also into covalent dynamic polymers and polymolecular assemblies.