Organic Chemistry Department, Faculty of Science, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia.
Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, bld. 4, Moscow 119071, Russia.
Molecules. 2023 Jan 25;28(3):1188. doi: 10.3390/molecules28031188.
An efficient approach to the synthesis of olefin metathesis HG-type catalysts containing an N→Ru bond in a six-membered chelate ring was proposed. For the most part, these ruthenium chelates can be prepared easily and in high yields based on the interaction between 2-vinylbenzylamines and (the common precursor for Ru-complex synthesis). It was demonstrated that the increase of the steric volume of substituents attached to the nitrogen atom and in the α-position of the benzylidene fragment leads to a dramatic decrease in the stability of the target ruthenium complexes. The bulkiest Pr substituent bonded to the nitrogen atom or to the α-position does not allow the closing of the chelate cycle. N,N-Diethyl-1-(2-vinylphenyl)propan-1-amine is a limiting case; its interaction with makes it possible to isolate the corresponding ruthenium chelate in a low yield (5%). Catalytic activity of the synthesized complexes was tested in RCM reactions and compared with α-unsubstituted catalysts obtained previously. The structural peculiarities of the final ruthenium complexes were thoroughly investigated using XRD and NMR analysis, which allowed making a reliable correlation between the structure of the complexes and their catalytic properties.
提出了一种在六元螯环中含有 N→Ru 键的烯烃复分解 HG 型催化剂的有效合成方法。在很大程度上，这些钌螯合物可以基于 2-乙烯基苄胺和 (Ru 配合物合成的常见前体)之间的相互作用，很容易且以高产率制备。结果表明，连接到氮原子和亚苄基片段的α-位上的取代基的空间体积增加会导致目标钌配合物的稳定性急剧下降。连接到氮原子或α-位的最大体积取代基Pr 不允许螯合环关闭。N,N-二乙基-1-(2-乙烯基苯基)丙-1-胺是一个限制情况；它与 相互作用，使得可以以低产率（5%）分离相应的钌螯合物。在 RCM 反应中测试了合成的配合物的催化活性，并与以前获得的α-未取代的催化剂进行了比较。使用 XRD 和 NMR 分析对最终的钌配合物的结构特性进行了彻底研究，这使得能够在配合物的结构与其催化性能之间建立可靠的相关性。
