25372-42-3Relevant articles and documents
Reactivity of Ruthenium(II) Complexes Bearing Bis-NHC Ligands
Dutschke, Patrick D.,Hahn, F. Ekkehardt,Hepp, Alexander,Lübbering, Tobias
supporting information, p. 3775 - 3784 (2021/11/17)
Bis-imidazolium salts bearing N-2-fluorobenzyl substituents and methylene, ethylene, or propylene linkers ([H2-4]Br2-[H2-6]Br2) and the bis-imidazolium salt [H2-8]Br2 featuring an ethylene linker and N-3-fluorophenyl substituents have been prepared. Salts [H2-5]Br2 and [H2-6]Br2 react with [RuCl2(CO)2]n to give the bis-NHC chelate complexes [9] and [10]. Chloride substitution in [10] for the 2-nitrophenyl isocyanide ligand 11 yielded the complex [12]PF6. The nitro group of the isocyanide in [12]PF6 could not be reduced. Salts [H2-4]Br2 and [H2-5]Br2 yield with [RuCp*(MeCN)3]PF6 the chelate complexes [13]PF6 and [14]PF6, respectively. The propylene-bridged bis-imidazolium salt [H2-6]Br2 reacts with [RuCp*(MeCN)3]PF6 to give, via an oxidative addition of a C-H bond of the central methylene group of the linker, the seven-coordinate RuIV complex [15]PF6 bearing a tridentate CNHCCalkylCNHC ligand and a hydrido ligand. Introduction of a nitrophenyl isocyanide ligand to [14]PF6 and reduction of the nitro group to the primary amine was also possible. Finally, [H2-8]Br2 reacts with [RuCp*(MeCN)3]PF6 to give, after intramolecular oxidative addition of a Caryl-H bond followed by reductive elimination of an imidazolium group, the complex [20]PF6 bearing a unique tridentate CarylCNHCC=Cimidazolium chelate ligand.
Steric effects on acetate-assisted cyclometallation ofmeta-substitutedN-phenyl andN-benzyl imidazolium salts at [MCl2Cp*]2(M = Ir, Rh)
Davies, David L.,Singh, Kuldip,Tamosiunaite, Neringa
, p. 13505 - 13515 (2021/10/12)
meta-SubstitutedN-phenyl,N′-methyl andN-benzyl,N′-methyl imidazolium salts undergo acetate-assisted cyclometallation to provide mixtures oforthoandparasubstituted cyclometallated complexes. The effect of the substituents on the isomer ratios is discussed; steric effects are more important in the 6-membered rings derived from theN-benzyl imidazolium salts than 5-membered rings from theN-phenyl salts. Comparisons are made to steric effects with some other common directing groups.
A facile one-step approach for the synthesis of uniform spherical Cu/Cu2O nano- and microparticles with high catalytic activity in the Buchwald-Hartwig amination reaction
Bhosale, Manohar A.,Bhanage, Bhalchandra M.
, p. 15122 - 15130 (2014/04/17)
In the present work, we have developed a rapid, one step, calcination-free protocol for the synthesis of uniform spherical Cu/Cu2O nano/microparticles (NMPs). The synthesis of Cu/Cu2O NMPs was achieved by microwave irradiation of copper acetate as a precursor and 1,4-butanediol as a solvent in a few minutes. The prepared Cu/Cu2O NMPs gave 100% yield of uniform spherical morphology. 1,4-Butanediol plays a crucial role in reactions such as a solvent, reactant, stabilizer and capping agent which control the crystal morphology. The resultant product was characterized with the help of different techniques such as XRD, FEG-SEM, EDS, TEM, FT-IR, TPR, DSC-TGA, XPS and BET surface area analysis. The results confirm that the Cu/Cu2O NMPs had good crystallinity and were essentially pure. This is a simple, faster, inexpensive and additive-free protocol for synthesis of nanocrystalline Cu/Cu2O compared to the conventional method. These Cu/Cu2O NMPs showed excellent catalytic activity in the Buchwald-Hartwig amination coupling reaction. Notably the reaction does not require any ligand source, and requires low catalyst loading, and low temperature with catalyst recyclability. the Partner Organisations 2014.
