1201005-45-9Relevant academic research and scientific papers
Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
, p. 1596 - 1611 (2020/04/29)
A series of new unsymmetrical (XYC–1 type) palladacycles (C1–C4) were designed and synthesized with simple anchoring ligands L1–4H (L1H = 2-((2-(4-methoxybenzylidene)-1-phenylhydrazinyl)methyl)pyridine, L2H = N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl)aniline, L3H = N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl) aniline and L4H = 4-(4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono) methyl)phenyl)morpholine H = dissociable proton). Molecular structure of catalysts (C1–C4) were further established by single X-ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate derivatives. During catalytic cycle in situ generated Pd(0) nanoparticles were characterized by XPS, SEM and TEM analysis and possible reaction pathways were proposed. The catalyst was employed as a pre-catalyst for the gram-scale synthesis of octinoxate, which is utilized as a UV-B sunscreen agent.
Dimetallic Palladium-NHC Complexes: Synthesis, Characterization, and Catalytic Application for Direct C?H Arylation Reaction of Heteroaromatics with Aryl Chlorides
Lee, Jhen-Yi,Ghosh, Debalina,Kuo, Ya-Ting,Lee, Hon Man
, p. 648 - 658 (2020/01/02)
A series of dimetallic palladium(II)-NHC complexes comprised of 1,4-naphthalenyl or 9,10-anthracenyl spacer sandwiched between two imidazole rings was successfully synthesized. These complexes were characterized by 1H and 13C{1H} NMR spectroscopy and elemental analysis. The structures of two dimetallic palladium complexes and a related mononuclear palladium complex to be used for comparative studies were further characterized by X-ray diffraction. The dimetallic palladium complex with the 9,10-anthracenyl linker was very efficient in catalyzing direct C?H arylation reactions of heteroaromatic compounds (imidazoles, imidazo[1,2-a]pyridine, and thioazole) with a broad range of aryl chlorides, employing a mild monopalladium loading of 1.5 mol%.It allows for the effective use of aryl chlorides to prepare arylated heterocycles, previously only accessible with the more reactive bromide counterparts. Importantly, the catalytic activity of the dimetallic precatalyst was found to be higher than that of an analogous mononuclear complex. (Figure presented.).
Imidazole-aryl coupling reaction via C[sbnd]H bond activation catalyzed by palladium supported on modified magnetic reduced graphene oxide in alkaline deep eutectic solvent
Shariatipour, Monire,Salamatmanesh, Arefe,Jadidi Nejad, Masoumeh,Heydari, Akbar
, (2019/11/20)
By employing reusable heterogeneous catalyst, modified magnetic reduced graphene oxide-supported palladium catalyst (MRGO@ DAP- AO-Pdll), the regioselective C-5 arylation of imidazoles via C[sbnd]H bond activation pathway for the preparation of
Palladium(II) Complexes of N-Heterocyclic Carbene Amidates Derived from Chalcogenated Acetamide-Functionalized 1 H-Benzimidazolium Salts: Recyclable Catalyst for Regioselective Arylation of Imidazoles under Aerobic Conditions
Bhaskar, Renu,Sharma, Alpesh K.,Singh, Ajai K.
, p. 2669 - 2681 (2018/09/10)
The chalcogenated acetamide-functionalized 1H-benzimidazolium salt precursors [1-(CH2C(O)NH(CH2)2S/SePh)-3-R-C7H5N2]+ X (L1-L4; R = Me, CH2Ph; X = Br, I) to C,N,S/Se l
Developing Bis(imino)acenaphthene-Supported N-Heterocyclic Carbene Palladium Precatalysts for Direct Arylation of Azoles
Hu, Li-Qun,Deng, Rong-Li,Li, Yan-Fen,Zeng, Cui-Jin,Shen, Dong-Sheng,Liu, Feng-Shou
supporting information, p. 214 - 226 (2018/02/06)
On the basis of the strategy of developing highly efficient protocol for Pd-catalyzed cross-coupling reactions, a series of bulky bis(imino)acenaphthene (BIAN)-supported Pd-PEPPSI complexes were synthesized, characterized, and applied in direct arylation
Sterically Encumbered Tetraarylimidazolium Carbene Pd-PEPPSI Complexes: Highly Efficient Direct Arylation of Imidazoles with Aryl Bromides under Aerobic Conditions
He, Xu-Xian,Li, Yinwu,Ma, Bei-Bei,Ke, Zhuofeng,Liu, Feng-Shou
supporting information, p. 2655 - 2663 (2016/09/04)
A series of sterically encumbered tetraarylimidazolium carbene Pd-PEPPSI complexes were conveniently prepared and fully characterized. These sterically encumbered Pd-PEPPSI complexes act as active precatalysts for the direct arylation of imidazoles with aryl bromides under aerobic conditions. The catalytic performance of Pd-PEPPSI complexes in cross-coupling processes is investigated. Under the optimal protocols, the cross-coupling reactions regioselectively produced C5-arylation products in moderate to excellent yields, which could tolerate a wide range of functional aryl bromides.
Direct C5-arylation reaction between imidazoles and aryl chlorides catalyzed by palladium complexes with phosphines and N-heterocyclic carbenes
Kumar, P. Vijaya,Lin, Wu-Shien,Shen, Jiun-Shian,Nandi, Debkumar,Lee, Hon Man
experimental part, p. 5160 - 5169 (2011/11/14)
Palladium(II) acetate complexes bearing phosphines and carbene ligands, Pd(L)(PR3)(OAc)2 (1a, R = Ph; 1b, R = Cy; L = 1,3-dibenzylimidazol-2-ylidene), were prepared by salt metathesis reactions of their chloro complexes with AgOAc in good yields. The electron-rich 1b was efficient in catalyzing C-5 direct arylation of imidazoles with aryl halides. Most significantly, the catalytic system allows a range of aryl chlorides as substrates. Microwave irradiation effectively promotes the reactions, with good yields obtainable in only 2 h. In combination with the classical method of C-C bond formation reactions, novel imidazole derivatives featuring biaryl and styryl subunits were successfully obtained from 1,4-dichlorobenzene and 1-bromo-4-chlorobenzene.
Phosphine-free palladium-catalysed direct 5-arylation of imidazole derivatives at low catalyst loading
Roger, Julien,Doucet, Henri
experimental part, p. 9772 - 9781 (2010/01/06)
The regioselective 5-arylation of imidazole derivatives with aryl bromides using a low loading of a phosphine-free palladium catalyst gives a simple and economic access to the corresponding 5-arylimidazoles. The choice of the base and of the solvent was f
