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.
Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
, p. 208 - 218 (2021/12/29)
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
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.
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.
