ChemInform Abstract: Direct C-H Bond Arylation of 2-Hydroxybenzaldehydes with Arylboronic Acids via Ligand-Free Palladium Catalysts.

ChemInform ◽  
2010 ◽  
Vol 41 (35) ◽  
pp. no-no
Author(s):  
Fei Weng ◽  
Chengming Wang ◽  
Bin Xu
Keyword(s):  
Palladium Catalysts ◽  
Arylboronic Acids ◽  
Ligand Free

scholarly journals Autocatalytic photoredox Chan-Lam coupling of free diaryl sulfoximines with arylboronic acids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cong Wang ◽  
Hui Zhang ◽  
Lucille A. Wells ◽  
Tian Liu ◽  
Tingting Meng ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom Abstraction ◽  
Coupling Reactions ◽  
Ambient Light ◽  
Environmental Friendliness ◽  
Copper Species ◽  
Arylboronic Acids ◽  
Ligand Free ◽  
Byproduct Formation ◽  
Electron Reduction

AbstractN-Arylation of NH-sulfoximines represents an appealing approach to access N-aryl sulfoximines, but has not been successfully applied to NH-diaryl sulfoximines. Herein, a copper-catalyzed photoredox dehydrogenative Chan-Lam coupling of free diaryl sulfoximines and arylboronic acids is described. This neutral and ligand-free coupling is initiated by ambient light-induced copper-catalyzed single-electron reduction of NH-sulfoximines. This electron transfer route circumvents the sacrificial oxidant employed in traditional Chan-Lam coupling reactions, increasing the environmental friendliness of this process. Instead, dihydrogen gas forms as a byproduct of this reaction. Mechanistic investigations also reveal a unique autocatalysis process. The C–N coupling products, N-arylated sulfoximines, serve as ligands along with NH-sulfoximine to bind to the copper species, generating the photocatalyst. DFT calculations reveal that both the NH-sulfoximine substrate and the N-aryl product can ligate the copper accounting for the observed autocatalysis. Two energetically viable stepwise pathways were located wherein the copper facilitates hydrogen atom abstraction from the NH-sulfoximine and the ethanol solvent to produce dihydrogen. The protocol described herein represents an appealing alternative strategy to the classic oxidative Chan-Lam reaction, allowing greater substrate generality as well as the elimination of byproduct formation from oxidants.

ChemInform Abstract: Base Promoted Highly Efficient Copper Fluorapatite Catalyzed Coupling of Phenols with Arylboronic Acids under Mild and Ligand-Free Conditions.

ChemInform ◽  
2013 ◽  
Vol 44 (16) ◽  
pp. no-no
Author(s):  
Shafeek A. R. Mulla ◽  
Suleman M. Inamdar ◽  
Mohsinkhan Y. Pathan ◽  
Santosh S. Chavan
Keyword(s):  
Arylboronic Acids ◽  
Highly Efficient ◽  
Ligand Free

Rapid Ligand-Free Base-Accelerated Copper-Catalyzed Homocoupling Reaction of Arylboronic Acids

Synlett ◽  
2016 ◽  
Vol 28 (05) ◽  
pp. 601-606 ◽  
Author(s):  
Feng Gao ◽  
Xian-Li Zhou ◽  
Ya-Nan Cao ◽  
Xin-Chuan Tian ◽  
Xing-Xiu Chen ◽  
...  
Keyword(s):  
Free Base ◽  
Arylboronic Acids ◽  
Ligand Free ◽  
Homocoupling Reaction

scholarly journals Development of Titanium Dioxide-Supported Pd Catalysts for Ligand-Free Suzuki–Miyaura Coupling of Aryl Chlorides

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 461 ◽  
Author(s):  
Yamada ◽  
Masuda ◽  
Park ◽  
Tachikawa ◽  
Ito ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Palladium Catalysts ◽  
Catalyst Activity ◽  
Acetonitrile Solution ◽  
Palladium Acetate ◽  
Tio2 Anatase ◽  
Aryl Chlorides ◽  
Donation Process ◽  
Ligand Free ◽  
Supported Pd

The catalyst activities of various heterogeneous palladium catalysts supported by anatase-, rutile- and brookite-type titanium oxide for ligand-free Suzuki–Miyaura cross-coupling reactions of aryl chlorides were evaluated. Palladium acetate [Pd(OAc)2], supported on anatase-type titanium oxide (TiO2) via acetonitrile solution impregnation process without reduction [Pd/TiO2 (anatase-type)], demonstrated the highest catalyst activity in comparison to those of other titanium oxide (rutile- or brookite-type) supported Pd(OAc)2 without reduction and reduced Pd/TiO2 (anatase-type) [Pd(red)/TiO2 (anatase-type)]. Various aryl chloride and bromide derivatives were smoothly coupled with arylboronic acids including heteroarylboronic acids in the presence of 5–10 mol% Pd/TiO2 (anatase-type) without the addition of any ligands. Although the fresh Pd/TiO2 (anatase-type) catalyst was surprisingly comprised of ca. 1:2 mixture of palladium(II) and palladium(0) species according to X-ray photoelectron spectroscopy (XPS), in spite of no reduction process, significant further increment of palladium(0) species was observed during the Suzuki–Miyaura coupling reaction, and Pd/TiO2 (anatase-type) was converted into a catalyst, which contained palladium(0) species as the main component [ca. 1:5 mixture of palladium(II) and palladium(0) species]. Therefore, the reduction via the electron donation process to the palladium(II) species may have occurred during the reaction on anatase-type titanium oxide.

Highly Efficient and Reusable Polyaniline-Supported Palladium Catalysts for Open-Air Oxidative Heck Reactions under Base- and Ligand-Free Conditions

2008 ◽  
Vol 350 (13) ◽  
pp. 1968-1974 ◽  
Author(s):  
Pravin R. Likhar ◽  
Moumita Roy ◽  
Sarabindu Roy ◽  
M. S. Subhas ◽  
M. Lakshmi Kantam ◽  
...  
Keyword(s):  
Palladium Catalysts ◽  
Heck Reactions ◽  
Supported Palladium Catalysts ◽  
Highly Efficient ◽  
Ligand Free ◽  
Supported Palladium
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