was determined by single-crystal X-ray diffraction study. The catalytic activities of all palladium complexes were evaluated in the direct C-H bond arylation of the 2-acetylfuran and 2-acetylthiophene with (hetero) aryl bromides and readily available and inexpensive aryl chlorides in presence of 1 mol% catalyst loading at 120 °C. Under the given conditions, (hetero)aryl halides were successfully applied
Ligand-less palladium-catalyzed direct 5-arylation of thiophenes at low catalyst loadings
作者:Julien Roger、Franc Požgan、Henri Doucet
DOI:10.1039/b819912d
日期:——
Ligand-less Pd(OAc)2 provides a very efficient catalyst for the direct5-arylation of thiophenederivatives. With this catalyst, a low palladium concentration (0.1–0.001 mol%) should be employed in order to obtain high yields of coupling products. At higher concentrations a fast formation of inactive “Pd black” generally occurs. Substrates/catalysts ratios up to 100000 can be employed with the most
Palladium associated with cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane (Tedicyp) was found to promote the direct 2-arylation of a variety of thiophene derivatives via CH functionalisation in good yields using very lowcatalystloadings. Electron-deficient, electron-excessive or sterically-congested aryl bromides are tolerated. Moreover, several substituents on the aryl bromide
Synthesis, structures, DFT calculations, and catalytic application in the direct arylation of five-membered heteroarenes with aryl bromides of novel palladium-N-heterocyclic carbene PEPPSI-type complexes
A new series of Pd-catalysts based on an N-heterocycliccarbene PEPPSI-type ligand (PEPPSI = pyridine enhanced precatalyst preparation stabilization and initiation) with the general formula [Pd(II)Br2(NHC)(pyridine)] was synthesized and fully characterized via spectroscopic analytical methods. Further, the structural characterization of 3a, 3b, and 3d was performed via single-crystal X-ray diffraction
A Zwitterionic Palladium(II) Complex as a Precatalyst for Neat-Water-Mediated Cross-Coupling Reactions of Heteroaryl, Benzyl, and Aryl Acid Chlorides with Organoboron Reagents
A zwitterionic palladium(II) complex has been found to be an efficient catalyst for Suzuki–Miyaura cross‐coupling reactions of aryl and heteroaryl organoboron reagents with various heteroaryl chlorides, aryl‐ and heteroarylmethyl chlorides, and aryl acid chlorides in neat water.