35717-20-5Relevant articles and documents
Mechanistic studies on the Pd-catalyzed direct C-H arylation of 2-substituted thiophene derivatives with arylpalladium bipyridyl complexes
Steinmetz, Marc,Ueda, Kirika,Grimme, Stefan,Yamaguchi, Junichiro,Kirchberg, Sylvia,Itami, Kenichiro,Studer, Armido
, p. 1256 - 1260 (2012)
Direct C-H phenylation of 2-ethylthiophene and 2-chlorothiophene with PhPdI(bipy) complex to form either the corresponding 4-phenyl or 5-phenylthiophene derivative is studied under stoichiometric conditions using various Lewis acids as additives. It is sh
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.
supporting information, p. 4687 - 4698 (2020/09/07)
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.).
Aerobic and Efficient Direct Arylation of Five-Membered Heteroarenes and Their Benzocondensed Derivatives with Aryl Bromides by Bulky α-Hydroxyimine Palladium Complexes
Luo, Bao-Tian,Liu, Huan,Lin, Zhi-Jie,Jiang, Jingxing,Shen, Dong-Sheng,Liu, Rui-Zhi,Ke, Zhuofeng,Liu, Feng-Shou
, p. 4881 - 4894 (2015/11/09)
In the present work, a series of α-hydroxyimine palladium complexes with bulky substituents (i.e., {[Ar-N=C(R)-C(R)2-OH]PdCl2} (C1, R = Me, Ar = 2-diphenylmethyl-4,6-dimethylphenyl; C2, R = Me, Ar = 2,6-bis(diphenylmethyl)-4-methylphenyl; C3, R = Me, Ar = 2,6-bis(diphenylmethyl)-4-methyoxylphenyl; C4, R = Me, Ar = 2,6-bis(diphenylmethyl)-4-chlorophenyl; C5, R = Ph, Ar = 2,6-dimethylphenyl; C6, R = Ph, Ar = 2,6-diisopropylphenyl)) were synthesized and characterized. The structures of palladium complexes C1 and C2 were determined by X-ray diffraction. These bidentate N,O-palladium complexes were applied for direct arylation under aerobic conditions. The effects of the reaction conditions and ligand substitution on the catalytic activity were evaluated. Upon a low palladium loading of 0.5 mol %, the bulky palladium complex C6 was successfully used to catalyze the cross-coupling of a variety of five-membered heteroarenes and their benzo-condensed derivatives with (hetero)aryl bromides. The mechanistic investigation on the direct arylation supported the involvement of a Pd(0)/Pd(II) CMD process.
