Easy-separable magnetic nanoparticle-supported Pd catalysts: Kinetics, stability and catalyst re-use
作者:Urszula Laska、Christopher G. Frost、Gareth J. Price、Pawel K. Plucinski
DOI:10.1016/j.jcat.2009.10.001
日期:2009.12.10
novel palladium-based catalysts supported on magnetic nanoparticles with diameters of 7–17 nm have been prepared and evaluated in C–C coupling, hydrogenation and amination reactions. One type of catalyst used palladium complexes containing phosphine and/or acetate ligands for applications in Suzuki and Heck reactions. The second type consisted of Pd(0)-functionalised magnetic cores for use in hydrogenation
Highly Efficient and Reusable Polyaniline-Supported Palladium Catalysts for Open-Air Oxidative Heck Reactions under Base- and Ligand-Free Conditions
作者:Pravin R. Likhar、Moumita Roy、Sarabindu Roy、M. S. Subhas、M. Lakshmi Kantam、B. Sreedhar
DOI:10.1002/adsc.200800329
日期:2008.9.5
Oxidative Heckreactions of arylboronic acids and alkenes are carried out in the presence of polyaniline-supported palladiumcatalysts using air as a co-oxidant to afford the Heck products with excellent yields and selectivities under base- and ligand-free conditions. The catalyst was recovered by simple filtration and used for several cycles with consistent activity.
Ligand- and copper-free Sonogashira and Heck couplings of (Het)aryl chlorides and bromides catalyzed by palladium nanoparticles supported on in situ generated Al(OH)<sub>3</sub>
ligand- and copper-free Sonogashirareaction of (Het)aryl halides (Br and Cl) with various terminal alkynes and the Heck coupling of (Het)aryl halides (Br and Cl) with a series of olefins, catalyzed by palladiumnanoparticles supported on newly generated Al(OH)3, were developed. The catalyst can be readily recovered and reused 6 times without significant loss of activity and palladium leaching.
The double protection of the organic cation [BMIM]+ and RGO can reduce the collision and agglomeration of Pd nanoparticles. Hence, the in situ prepared Pd/RGO can exhibit high efficiency and long-term catalytic stability for the Heck reaction in the ionic liquid.
Efficient Palladium(II) Precatalysts Bearing 4,5‐Dicyanoimidazol‐2‐ylidene for the Mizoroki–Heck Reaction
作者:Heiko Baier、Philipp Metzner、Thomas Körzdörfer、Alexandra Kelling、Hans‐Jürgen Holdt
DOI:10.1002/ejic.201402040
日期:2014.6
[PdCl2(PhCN)(2)]. The three palladium(II) complexes were characterized by NMR and IR spectroscopy, mass spectrometry and elemental analysis. In addition, the molecular structures of 2 and 3 were determined by X-ray diffraction. The pi-acidity of (CN)(2)IBzPic was compared with (CN)(2)IMes and perviously reported pi-acidic imidazol-2-ylidenes by NBO analysis. The Mizoroki-Heck (MH) reactions of various