960205-03-2Relevant academic research and scientific papers
Cationic Rh and Ir complexes containing bidentate imidazolylidene-1,2,3- triazole donor ligands: Synthesis and preliminary catalytic studies
Vuong, Khuong Q.,Timerbulatova, Marina G.,Peterson, Matthew B.,Bhadbhade, Mohan,Messerle, Barbara A.
supporting information, p. 14298 - 14308 (2013/10/01)
A series of new cationic Rh(i), Rh(iii) and Ir(iii) complexes containing hybrid bidentate N-heterocyclic carbene-1,2,3-triazolyl donor of general formulae [Rh(CaT)(COD)]BPh4 (2a-d), [Rh(CaT)(CO)2]BPh 4 (3a-d) and [M(CaT)(Cp*)Cl]BPh4 (M = Rh, 4a-d; M = Ir, 5a-c), where CaT = bidentate N-heterocyclic carbene-triazolyl ligands, COD = 1,5-cyclooctadiene and Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl, were synthesised. The imidazolium-1,2,3-triazolyl pre-ligands (1a-c and 1e-i) were readily prepared using the Cu(i) catalysed 'click reaction' between phenyl azide or benzyl azides with propargyl functionalised imidazolium salts. The single crystal solid state structures of complexes 2a-d; 3a-b; 4a-d and 5a-b confirm the bidentate coordination of the NHC-1,2,3-triazolyl ligand with the NHC coordinating via the 'normal' C2-carbon and the 1,2,3-triazolyl donor coordinating via the N3′ atom to form six membered metallocycles. These complexes are the first examples of Rh and Ir complexes containing the hybrid NHC-1,2,3-triazolyl ligands which exhibit a bidentate coordination mode. A number of these complexes showed limited efficiency as catalysts for the intramolecular hydroamination of 4-pentyn-1-amine to 2-methylpyrroline.
A simple procedure for polymer-supported N-heterocyclic carbene silver complex via click chemistry: An efficient and recyclable catalyst for the one-pot synthesis of propargylamines
He, Ying,Lv, Mei-Fang,Cai, Chun
, p. 12428 - 12433,6 (2020/09/09)
A series of polymer-supported N-heterocyclic carbene silver complexes were prepared using a simple procedure via click chemistry. These complexes were tested as catalysts in the synthesis of propargylamines by the one-pot three-component coupling reaction
Click ionic liquids: A family of promising tunable solvents and application in Suzuki-Miyaura cross-coupling
Li, Liuyi,Wang, Jinyun,Wu, Tao,Wang, Ruihu
experimental part, p. 7842 - 7851 (2012/08/07)
A series of click ionic salts 4a-4n was prepared through click reaction of organic azides with alkynefunctionalized imidazolium or 2-methylimidazolium salts, followed by metathesis with lithium bis(trifluoromethanesulfonyl) amide or potassium hexafluorophosphate. All salts were characterized by IR, NMR, TGA, and DSC, and most of them can be classified as ionic liquids. Their steric and electronic properties can be easily tuned and modified through variation of the aromatic or aliphatic substituents at the imidazolium and/or triazolyl rings. The effect of anions and substituents at the two rings on the physicochemical properties was investigated. The charge and orbital distributions based on the optimized structures of cations in the salts were calculated. Reaction of 4a with PdCl2 produced mononuclear click complex 4a-Pd, the structure of which was confirmed by single-crystal X-ray diffraction analysis. Suzuki-Miyaura cross-coupling shows good catalytic stability and high recyclability in the presence of PdCl2 in 4a. TEM and XPS analyses show formation of palladium nanoparticles after the reaction. The palladium NPs in 4a are immobilized by the synergetic effect of coordination and electrostatic interactions with 1,2,3-triazolyl and imidazolium, respectively.
Modular synthesis of bidentate triazolyl-functionalized N-heterocyclic carbenes and their palladium complexes
Warsink, Stefan,Drost, Ruben M.,Lutz, Martin,Spek, Anthony L.,Elsevier, Cornelis J.
experimental part, p. 3109 - 3116 (2010/12/18)
New heterobidentate N-heterocyclic carbene-triazolyl ligands and several of their palladium(II) complexes have been synthesized in a modular fashion using click chemistry. These complexes are the first examples where triazolyl-substituted NHCs exhibit bidentate behavior, which was confirmed by NMR and X-ray diffraction studies. The synthesis of the complexes could be achieved in relatively few steps by introducing the diversity at a late stage in the synthesis. The complexes are active precatalysts in the transfer semihydrogenation of alkynes to Z-alkenes, with activity and selectivity depending on the triazolyl substituent and the NHC nitrogen substituent. Selectivities as high as 99% were observed.
Triazole-functionalized N-heterocyclic carbene complexes of palladium and platinum and efficient aqueous Suzuki-Miyaura coupling reaction
Gu, Shaojin,Xu, Hui,Zhang, Na,Chen, Wanzhi
experimental part, p. 1677 - 1686 (2011/08/05)
Imidazolium salts bearing triazole groups are synthesized via a copper catalyzed click reaction, and the silver, palladium, and platinum complexes of their N-heterocyclic carbenes are studied. [Ag4(L1) 4](PF6)4, [Pd(L1)Cl](PF6), [Pt(L1)Cl](PF6) (L1=3-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)-1- (pyrimidin-2-yl)-1H-imidazolylidene), [Pd2(L2)2Cl 2](PF6)2, and [Pd(L2)2](PF 6)2 (L2=1-butyl-3-((1-(pyridin-2-yl)-1H-1,2,3-triazol-4- yl)methyl) imidazolylidene) have been synthesized and fully characterized by NMR, elemental analysis, and X-ray crystallography. The silver complex [Ag 4(L1)4](PF6)4 consists of a Ag 4 zigzag chain. The complexes [Pd(L1)Cl](PF6) and [Pt(L1)Cl](PF6), containing a nonsymmetrical NCN' pincer ligand, are square planar with a chloride trans to the carbene donor. [Pd 2(L2)2Cl2](PF6)2 consists of two palladium centers with CN2Cl coordination mode, whereas the palladium in [Pd(L2)2](PF6)2 is surrounded by two carbene and two triazole groups with two uncoordinated pyridines. The palladium compounds are highly active for Suzuki-Miyaura cross coupling reactions of aryl bromides and 1,1-dibromo-1-alkenes in neat water under an air atmosphere.
