449736-97-4Relevant articles and documents
The site-selectivity and mechanism of Pd-catalyzed C(sp2)-H arylation of simple arenes
Kim, Daeun,Choi, Geunho,Kim, Weonjeong,Kim, Dongwook,Kang, Youn K.,Hong, Soon Hyeok
, p. 363 - 373 (2021/01/14)
Control over site-selectivity is a critical challenge for practical application of catalytic C-H functionalization reactions in organic synthesis. Despite the seminal breakthrough of the Pd-catalyzed C(sp2)-H arylation of simple arenes via a concerted metalation-deprotonation (CMD) pathway in 2006, understanding the site-selectivity of the reaction still remains elusive. Here, we have comprehensively investigated the scope, site-selectivity, and mechanism of the Pd-catalyzed direct C-H arylation reaction of simple arenes. Counterintuitively, electron-rich arenes preferably undergo meta-arylation without the need for a specifically designed directing group, whereas electron-deficient arenes bearing fluoro or cyano groups exhibit high ortho-selectivity and electron-deficient arenes bearing bulky electron-withdrawing groups favor the meta-product. Comprehensive mechanistic investigations through a combination of kinetic measurements and stoichiometric experiments using arylpalladium complexes have revealed that the Pd-based catalytic system works via a cooperative bimetallic mechanism, not the originally proposed monometallic CMD mechanism, regardless of the presence of a strongly coordinating L-type ligand. Notably, the transmetalation step, which is influenced by a potassium cation, is suggested as the selectivity-determining step.
Sulfadiazine iron palladium nano-composite particle and preparation method thereof
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Paragraph 0030; 0031, (2018/02/04)
The invention discloses a sulfadiazine iron palladium nano composite particle and a preparation method thereof. According to the invention, two metal salt solutions, at a certain ratio, are added in a sulfadiazine-containing organic ligand. The obtained product is subjected to hydrothermal reaction at a certain temperature. After the reaction is over, the obtained product is cooled to the room temperature, filtered and dried to obtain a corresponding metal-ligand nano composite particle. The method is simple in preparation process, low in cost and suitable for mass production. Through controlling the amounts of reactants, the reaction time and the reaction temperature, the particle size of the sulfadiazine iron palladium nano composite particle and the dispersibility thereof are effectively controlled. The prepared sulfadiazine iron palladium nano composite particle is a functionalized nano particle containing iron and palladium, and is stable in performance. The particle can be used for catalyzing the C-C bond coupling reaction, and is high in catalytic efficiency. The yield can be up to over 95% by adopting the particle. Therefore, the sulfadiazine iron palladium nano composite particle has a wide application prospect in the catalysis field.
Trace amount CuII (ppm) and mixture design of CuII/PdII catalyzed Suzuki cross-coupling reactions based on the cooperative interaction of metal with a conjugated pyridylspirobifluorene
Li, Xing,Zhang, Jie,Zhao, Yayun,Zhao, Xiuhua,Li, Feng,Li, Taohai,Li,Chen, Liang
supporting information, p. 6265 - 6270 (2015/03/18)
Self-assembly of Cu/psf sheets and layer-by-layer (LbL) growth of PEI-(Cu/psf)n films were carried out and characterized (psf = 2,2′,7,7′-tetra(4-pyridyl)-9,9′-spirobifluorene). A mixture design was performed to evaluate the singular and combined catalytic effects of Cu(ii), Pd(ii) and psf ligands in the Suzuki cross-coupling reactions. The results showed that copper exhibited high catalytic activities in the presence of psf ligands. The (CuII/psf)n films were used as the reservoirs of catalysts capable of gradually discharging highly active catalytic moieties to promote the coupling reactions with ultra low Cu-loadings (as low as 1.4 × 10-5 mol%). This journal is
