2-亚胺咪唑烷类钯催化剂的合成及研究
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摘要
为了提高后过渡金属催化剂的催化性能,结合2-亚胺咪唑烷强供电子性的特点,笔者设计合成了全新的钯催化剂。通过X-射线单晶衍射仪测试,确定了配合物分子的空间结构,发现与中心金属相连的甲基容易被氯原子取代,当配合物空间位阻较大时,容易发生C-H活化现象。同时也研究了配合物对降冰片烯的催化性能,吸电子F的引入,配合物的热稳定性提高,聚合过程中的链转移反应增强。
To improve the performance of late transition metal catalysts, combined with the strong electron donating ligand of 2-imine imidazolidine, we designed and synthesized novel palladium complexes. The structure of the complex was determined by X-ray single crystal analysis. The results showed that the methyl group attached to the central metal was easily replaced by a chlorine atom, and C-H activation was likely to occur due to the large steric hindrance of the complex. The catalytic performance of the complex on norbornene was also studied. The results showed that the introduction of electron-withdrawing F improved the thermal stability of the complex and the chain transfer reaction during polymerization.
To improve the performance of late transition metal catalysts, combined with the strong electron donating ligand of 2-imine imidazolidine, we designed and synthesized novel palladium complexes. The structure of the complex was determined by X-ray single crystal analysis. The results showed that the methyl group attached to the central metal was easily replaced by a chlorine atom, and C-H activation was likely to occur due to the large steric hindrance of the complex. The catalytic performance of the complex on norbornene was also studied. The results showed that the introduction of electron-withdrawing F improved the thermal stability of the complex and the chain transfer reaction during polymerization.
引文
[1] 谢丹妮, 霍丹, 司传领. 两种氮杂环卡宾Pd(Ⅱ)配合物的合成及表征[J]. 天津科技大学学报, 2018, 33(3):34-39.
[2] Zhou X, Jordan R. Synthesis, cis/trans isomerization, and reactivity of palladium alkyl complexes that contain a chelating N-Heterocyclic-Carbene sulfonate ligand[J]. Organometallics, 2011, 30(17): 4632-4642.
[3] Nakano R, Nozaki K. Copolymerization of propylene and polar monomers using Pd/IzQO catalysts[J]. Journal of the American Chemical Society, 2015, 137(34): 10934.
[4] Andrew W, Grubbs R. A new class of Chelating N-Heterocyclic carbene ligands and their complexes with palladium[J]. Organometallics, 2004, 23(13): 3105-3107.
[5] Sujith S, Eun K. Synthesis, characterization, and norbornene polymerization of η3-benzylnickel(II) complexes of N-heterocyclic carbenes[J]. Journal of Organometallic Chemistry, 2008, 693(12): 2171-2176.
[6] Li M, Shu X, Cai Z. Synthesis, structures, and norbornene polymerization behavior of neutral nickel(ii) and palladium(ii) complexes bearing aryloxide imidazolidin-2-imine ligands[J]. Organometallics, 2018, 37(7): 1172-1180.
[7] Kawahata M, Yamaguchi K, Ishikawa T. Bisguanidinobenzene, a Powerful hydrogen acceptor: crystal structures of organic complexes with benzoic acid, phenol, and benzyl alcohol[J]. Crystal Growth and Design, 2005, 5(1): 373-377.
[8] Yang D, Chen Y, Zhu N. Sterically bulky thioureas as Air- and Moisture-Stable ligands for Pd-Catalyzed heck reactions of aryl halides.[J]. Organic Letters, 2004, 6(10): 1577-1580.
[9] Wim D, Jaap B, Smeets W, et al. Dimethyl(N,N,N′, N′-tetramethylethanediamine)palladium(II) and dimethyl[1,2-bis(dimethylphosphino)ethane]palladium(II): syntheses, x-ray crystal structures, and thermolysis, oxidative-addition and ligand-exchange reactions[J]. Organometallics, 1989, 8(12):2907-2917.
[10] Labinger J A, Bercaw J E. Understanding and exploiting C-H bond activation[J]. Cheminform, 2002, 33(48):507-14.
[2] Zhou X, Jordan R. Synthesis, cis/trans isomerization, and reactivity of palladium alkyl complexes that contain a chelating N-Heterocyclic-Carbene sulfonate ligand[J]. Organometallics, 2011, 30(17): 4632-4642.
[3] Nakano R, Nozaki K. Copolymerization of propylene and polar monomers using Pd/IzQO catalysts[J]. Journal of the American Chemical Society, 2015, 137(34): 10934.
[4] Andrew W, Grubbs R. A new class of Chelating N-Heterocyclic carbene ligands and their complexes with palladium[J]. Organometallics, 2004, 23(13): 3105-3107.
[5] Sujith S, Eun K. Synthesis, characterization, and norbornene polymerization of η3-benzylnickel(II) complexes of N-heterocyclic carbenes[J]. Journal of Organometallic Chemistry, 2008, 693(12): 2171-2176.
[6] Li M, Shu X, Cai Z. Synthesis, structures, and norbornene polymerization behavior of neutral nickel(ii) and palladium(ii) complexes bearing aryloxide imidazolidin-2-imine ligands[J]. Organometallics, 2018, 37(7): 1172-1180.
[7] Kawahata M, Yamaguchi K, Ishikawa T. Bisguanidinobenzene, a Powerful hydrogen acceptor: crystal structures of organic complexes with benzoic acid, phenol, and benzyl alcohol[J]. Crystal Growth and Design, 2005, 5(1): 373-377.
[8] Yang D, Chen Y, Zhu N. Sterically bulky thioureas as Air- and Moisture-Stable ligands for Pd-Catalyzed heck reactions of aryl halides.[J]. Organic Letters, 2004, 6(10): 1577-1580.
[9] Wim D, Jaap B, Smeets W, et al. Dimethyl(N,N,N′, N′-tetramethylethanediamine)palladium(II) and dimethyl[1,2-bis(dimethylphosphino)ethane]palladium(II): syntheses, x-ray crystal structures, and thermolysis, oxidative-addition and ligand-exchange reactions[J]. Organometallics, 1989, 8(12):2907-2917.
[10] Labinger J A, Bercaw J E. Understanding and exploiting C-H bond activation[J]. Cheminform, 2002, 33(48):507-14.