159448-39-2Relevant academic research and scientific papers
A Convoluted Polyvinylpyridine-Palladium Catalyst for Suzuki-Miyaura Coupling and C?H Arylation
Ohno, Aya,Sato, Takuma,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
, p. 4687 - 4698 (2020)
The development of highly active and reusable supported catalysts for Suzuki-Miyaura coupling and catalytic C?H arylation is important for fundamental and applied chemistry, with these reactions being used to produce medical compounds and functional materials. Herein, we found that a mesoporous composite made of a linear poly(4-vinylpyridine) and tetrachloropalladate acted as a dual-mode catalyst for a variety of cross-coupling reactions, with both Pd nanoparticles and a Pd complex catalyst being observed under different conditions. The polyvinylpyridine-palladium composite 1 was readily prepared via the molecular convolution of poly(4-vinylpyridine) and sodium tetrachloropalladate to provide a hardly soluble polymer-metal composite. The Suzuki-Miyaura coupling and the C?H arylation of aryl chlorides and bromides with arylboronic acids, thiophenes, furans, benzene, and anisole proceeded in the presence of 0.004 mol% (40 mol ppm) to 1 mol% Pd of 1 to afford the corresponding coupling products in high yields. Furthermore, the catalyst was reused without an appreciable loss of activity. Pharmaceutical compounds and functional materials were synthesized via the coupling reactions. N2 gas adsorption/desorption analysis indicated that the catalyst had a mesoporous nature, which played a crucial role in the catalysis. In the Suzuki-Miyaura couplings, in situ generated palladium nanoparticles in the polymer matrix were catalytically active, while a polymeric Pd(II) complex was crucial in the C?H arylations. These catalytic species were investigated via XAFS, XPS, far-infrared absorption, and Raman spectroscopies, as well as DFT calculations. (Figure presented.).
Well-Defined Palladium N-Heterocyclic Carbene Complexes: Direct C-H Bond Arylation of Heteroarenes
Kumar, Anuj,Kumar, Manoj,Verma, Akhilesh K.
supporting information, p. 13983 - 13996 (2020/11/20)
A series of palladium N-heterocyclic carbene (NHC) complexes of type trans-{(NHC)PdCl2L} (L = C5H5N, 3-ClC5H4N, and PPh3) (3-5) have been developed as efficient precatalysts for direct C-H bond arylation of various heteroarenes. In particular, an in situ generated new NHC ligand derived from {1,3-di-(2,6-diethylphenyl)acenaphtho[1,2-d] imidazolium} chloride (2) is used for the stabilization of the palladium metal center. Among the screened palladium precatalysts (3-5), the most active PEPPSI themed complex (3) was successfully employed toward direct C-H bond arylation of various heteroarenes and aryl bromides. A range of functional groups on aryl bromides as well as on heteroarenes sustained throughout the standard reaction conditions for easy access of various arylated heterocyclic compounds. Significantly, the utility of the protocol was demonstrated by the effective synthesis of a precursor of raloxifene, a selective estrogen receptor modulator.
Direct c-h/c-h cross-coupling of benzimidates with heteroarenes to access biheteroaryl-2-carbonitriles
Wang, Zhigang,Wang, Fei,Liu, Zheng,He, Shuang,Pu, Xingwen,Yang, Yudong,Gao, Ge
supporting information, p. 10599 - 10602 (2019/09/06)
A Rh-catalyzed C-H/C-H oxidative cross-coupling reaction of benzimidates with heteroarenes is developed, yielding biheteroaryl-2-carbonitriles directly after in situ dealcoholization. This protocol features high atom- and step-economy, and a broad substrate scope with good functional group tolerance.
Cu-Catalyzed Denitrogenative Ring-Opening of 3-Aminoindazoles for the Synthesis of Aromatic Nitrile-Containing (Hetero)Arenes
Zhou, Yao,Deng, Shuilin,Mai, Shaoyu,Song, Qiuling
supporting information, p. 6161 - 6165 (2018/10/05)
An unprecedented Cu-catalyzed oxidative cleavage of two C-N bonds of 3-aminoindazoles is reported herein, which represents the first example for denitrogenative ring-opening of 3-aminoindazoles. This novel reactivity of 3-aminoindazoles enables the produc
Palladium-catalyzed direct arylation of heteroaromatic compounds: Improved conditions utilizing controlled microwave heating
Baghbanzadeh, Mostafa,Pilger, Christian,Oliver Kappe
experimental part, p. 8138 - 8142 (2011/11/07)
A versatile and rapid microwave-assisted procedure for the palladium-catalyzed direct arylation of heterocycles by aryl bromides and heteroaryl bromides is described. This novel protocol features short coupling times (10-60 min) and low catalyst loadings
Aversatile palladium/triphosphane system for direct arylation of heteroarenes with chloroarenes at low catalyst loading
Roy, David,Mom, Sophal,Beauperin, Matthieu,Doucet, Henri,Hierso, Jean-Cyrille
supporting information; experimental part, p. 6650 - 6654 (2010/12/25)
Put a ring on it: The use of an air-stable, robust palladium/tridentate phosphane catalyst in direct C-H and C-Cl activation reactions is reported (see scheme; DMAc=N,N-dimethylacetamide, TBAB=tetra-n-butylammonium bromide). Electron-rich, electron-poor, and polysubstituted furans (X=O), thiophenes (X=S), pyrroles (X=NR5), and thiazoles were arylated with chloroarenes in the presence of the catalyst.
