92-66-0Relevant articles and documents
Berliner et al.
, p. 1633 (1961)
Transfer of heterocyclic carbene ligands from chromium to gold, palladium and platinum
Kessler, Florian,Szesni, Normen,Maa?, Chaya,Hohberger, Christiane,Weibert, Bernhard,Fischer, Helmut
, p. 3005 - 3018 (2007)
The reaction of pentacarbonyl(pyrazolin-3-ylidene)chromium complexes, {A figure is presented} (2a-c) (R = Ph (a), C6H4NMe2-4 (b); (C5H4)FeCp (c)), with [AuCl(SMe2)], H[AuCl4], [PdCl2(NCPh)2] and [PtCl2(NCPh)2] gives, by transfer of the heterocyclic carbene ligand, new chloro pyrazolin-3-ylidene complexes of gold(I) and gold(III), dichloro bis(pyrazolin-3-ylidene) palladium and dichloro bis(pyrazolin-3-ylidene) platinum in high yield. The chloride ligand in {A figure is presented} (Fc = (C5H4)FeCp) is readily displaced by trifluoroacetate. The analogous substitution of iodide for the chloride ligands in {A figure is presented} (M = Pd, Pt) give the corresponding diiodo complexes although in a much slower reaction. In contrast, the reaction of silver trifluoroacetate with {A figure is presented} affords a binuclear Pd-Ag complex containing two pyrazolin-3-ylidene and three trifluoroacetate ligands two of whom occupy bridging positions between Pd and Ag. The reactions of the pyrazolidin-3-ylidene complex {A figure is presented} (R = C6H4NMe2-4) with [AuCl(SMe2)] and [PdCl2(NCPh)2] yield chloro pyrazolidin-3-ylidene gold and dichloro bis(pyrazolidin-3-ylidene) palladium complexes. The related dichloro bis(tetrahydropyrimidin-4-ylidene) palladium complex is formed in the reaction of {A figure is presented} with the palladium complex [PdCl2(NCPh)2]. The solid-state structures of several of these heterocyclic carbene complexes including the structure of the binuclear Pd-Ag complex are established by X-ray structure analyses.
Sterically enhanced 2-iminopyridylpalladium chlorides as recyclable ppm-palladium catalyst for Suzuki–Miyaura coupling in aqueous solution
Lin, Wenhua,Zhang, Liping,Ma, Yanping,Liang, Tongling,Sun, Wen-Hua
, (2021/10/20)
Sterically hindered 2-iminopyridine derivatives and their palladium chlorides complexes are designed and prepared, which efficiently promote the Suzuki–Miyaura coupling (SMC) reaction in aqueous solution. Besides the good to excellent yields and broad substrate scope, these catalysts can be reused for at least four new batches of the substrates. Spontaneous separation of coupling products in the aqueous reaction medium is the additional striking feature of this catalytic process. Furthermore, catalytic performance of palladium complexes bearing the azo-bridged phenyl groups was greatly influenced by the UV irradiation due to the cis/trans photoisomerization of azo unit of the catalysts. In conclusion, titled palladium complexes provide a green, sustainable, cost-effective, and convenient process to synthesize SMC products at multi-gram-scale reaction.
Recycling Oryza sativa wastes into poly-imidazolium acetic acid-tagged nanocellulose Schiff base supported Pd nanoparticles for applications in cross-coupling reactions
Elshaarawy, Reda F. M.,Yahya, Rana
, (2021/12/22)
A green and sustainable heterogeneous nanocatalyst for the Suzuki reaction was fabricated by refining rice straw to ionic nanocellulose Schiff base (NCESB) which was employed for bio-reduction of Pd(II) into Pd nanoparticles (Pd NPs) and immobilization of these NPs to fabricate the desired nanocatalyst (NCESB@Pd). The TEM image revealed well-dispersed PdNPs with sizes of 5–23 nm. The new nanocatalyst displayed amazing activity in catalyzing coupling reactions of a wide range of halobenzenes with phenylboronic acid at 50 °C (reaction time 15–60 min) and even at room temperature (reaction time 120 min). The NCESB@Pd nanocatalyst exhibited excellent recyclability (up to five catalytic runs) without a significant loss of its activity or identity. Therefore, the new ionic nanocatalyst may open a new window for a novel generation of ionic low-cost green and highly effective nanocatalysts for organic transformation reactions.
Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
Medina-Mercado, Ignacio,Porcel, Susana
, (2022/03/15)
A gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoroborate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.