56463-13-9Relevant articles and documents
N-Heterocyclic Carbene (NHC)-Stabilized Ru0 Nanoparticles: In Situ Generation of an Efficient Transfer Hydrogenation Catalyst
Kathuria, Lakshay,Din Reshi, Noor U.,Samuelson, Ashoka G.
, p. 7622 - 7630 (2020/05/29)
Tethered and untethered ruthenium half-sandwich complexes were synthesized and characterized spectroscopically. X-ray crystallographic analysis of three untethered and two tethered Ru N-heterocyclic carbene (NHC) complexes were also carried out. These RuNHC complexes catalyze transfer hydrogenation of aromatic ketones in 2-propanol under reflux, optimally in the presence of (25 mol %) KOH. Under these conditions, the formation of 2–3 nm-sized Ru0 nanoparticles was detected by TEM measurements. A solid-state NMR investigation of the nanoparticles suggested that the NHC ligands were bound to the surface of the Ru nanoparticles (NPs). This base-promoted route to NHC-stabilized ruthenium nanoparticles directly from arene-tethered ruthenium–NHC complexes and from untethered ruthenium–NHC complexes is more convenient than previously known routes to NHC-stabilized Ru nanocatalysts. Similar catalytically active RuNPs were also generated from the reaction of a mixture of [RuCl2(p-cymene)]2 and the NHC precursor with KOH in isopropanol under reflux. The transfer hydrogenation catalyzed by these NHC-stabilized RuNPs possess a high turnover number. The catalytic efficiency was significantly reduced if nanoparticles were exposed to air or allowed to aggregate and precipitate by cooling the reaction mixtures during the reaction.
Mechanistic study of a switch in the regioselectivity of hydroheteroarylation of styrene catalyzed by bimetallic Ni-Al through C-H activation
Chen, Wen-Ching,Lai, Ying-Chieh,Shih, Wei-Chun,Yu, Ming-Shiuan,Yap, Glenn P. A.,Ong, Tiow-Gan
supporting information, p. 8099 - 8105 (2014/07/07)
We previously reported a highly efficient protocol for bimetallic Ni-Al-catalyzed hydroheteroarylation of styrene with benzimidazole based on C-H bond activation. We have now delineated the mechanism of this process, providing a rationale for an observed switch in regioselectivity in the presence of the Lewis acid, AlMe3. The present mechanistic study gives insights for the rational development of catalysts that exhibit required linear/branched selectivity. Lewis acid switches regioselectivity: The mechanism underpinning a highly efficient protocol for bimetallic Ni-Al-catalyzed hydroheteroarylation of styrene with benzimidazole based on C-H bond activation has been unraveled (see scheme). The study gives insights that can be used for the rational development of catalysts that give the required linear/branched selectivity.
Synthesis, crystal structure and magnetic properties of a nickel(III) maleonitriledithiolate complex using 1-methyl-3-benzylbenzimidazolium cation
Dang, Dongbin,Ni, Chunlin,Bai, Yan,Tian, Zhengfang,Wen, Lili,Meng, Qingjin,Gao, Song
, p. 197 - 200 (2007/10/03)
A new ion-pair complex, 1-methyl-3-benzylbenzimidazolium bis(maleonitrile-dithiolato)nickelate(III), has been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. In solid state, the Ni(mnt)2-/su
