Synthesis and Characterization of Pyrazolyl-Functionalized Imidazolium-Based Ionic Liquids and Hemilabile (Carbene)palladium(II) Complex Catalyzed Heck Reaction
作者:Ruihu Wang、Zhuo Zeng、Brendan Twamley、Melissa M. Piekarski、Jean'ne M. Shreeve
DOI:10.1002/ejoc.200600828
日期:2007.2
Neat reactions of 1-(pyrazolylmethyl)imidazole with an excess of alkyl or polyfluoroalkyl halides at 100 °C followed by subsequent metathetical reactions with LiN(SO2CF3)2 or KPF6 at 25 °C gave rise to a series of monoquaternary salts 3a–3k. These salts can be also prepared through treatment of 1-alkylimidazole with 1-(chloromethyl)pyrazole hydrochloride in the presence of base, followed by anion exchange
Rhodium(i) and iridium(i) complexes of pyrazolyl-N-heterocyclic carbene ligands
作者:Barbara A. Messerle、Michael J. Page、Peter Turner
DOI:10.1039/b603455a
日期:——
Several Rh(I) and Ir(I) complexes containing an N-heterocyclic carbene-pyrazolyl chelate ligand have been synthesised. Determination of the single-crystal X-ray structure of the Ir(I) complex showed a novel binding mode with the iridium centre coordinated to two ligands via two carbene donors in preference to one ligand forming the entropically favoured chelate. The hydrogenation activity of several