Fluorinated biphenyls from aromatic arylations with pentafluorobenzenediazonium and related cations. Competition between arylation and azo coupling
作者:Dmitry Kosynkin、T. Michael Bockman、Jay K. Kochi
DOI:10.1039/a701745f
日期:——
High yields of the mixed perfluorinated biaryls (C6F5–Ar) are obtained by the catalytic dediazoniation of the pentafluorobenzenediazonium salt (C6F5N2+BF4–) in acetonitrile solutions containing various aromatic substrates (ArH) together with small amounts of iodide salts. Activated (electron-rich) as well as deactivated (electron-poor) arenes are successfully pentafluorophenylated by this method. The arylation is distinct from the azo coupling of the same substrates, which takes place in the absence of the iodide catalyst and yields the corresponding diazene (C6F5NN–Ar) as product. The catalytic role of iodide, and the isomeric product distributions obtained with this procedure indicate that the arylation proceeds via the pentafluorophenyl radical in a efficient homolytic chain process. Since azo coupling involves electrophilic aromatic substitution of electron-rich ArH by C6F5N2+, the two competing pathways are distinct and do not have reactive intermediates in common.
Copper-Catalyzed Decarboxylative Cross-Coupling of Potassium Polyfluorobenzoates with Aryl Iodides and Bromides
作者:Rui Shang、Yao Fu、Yan Wang、Qing Xu、Hai-Zhu Yu、Lei Liu
DOI:10.1002/anie.200904916
日期:2009.11.23
For copper only: The decarboxylative cross‐coupling of readily accessible and nonvolatile potassiumpolyfluorobenzoates with aryliodides and bromides using a copper catalyst provides polyfluorobiaryls and polyfluorostilbenes in excellent yields (see scheme). Mechanistic analyses are reported for the title reaction.
Palladium-Catalyzed Solid-State Polyfluoroarylation of Aryl Halides Using Mechanochemistry
作者:Rikuro Takahashi、Tamae Seo、Koji Kubota、Hajime Ito
DOI:10.1021/acscatal.1c03731
日期:2021.12.17
products. Here, we show that solid-state high-temperature ball-milling conditions facilitate a palladium-catalyzed cross-coupling with polyfluorinated arylboronic acids and pinacol esters employing a simple catalytic system in the absence of any stoichiometric additives. This reaction exhibits a broad substrate scope and can be carried out in air, and the use of large amounts of dry and degassed organic solvents
Synthesis and structural characterization of the first unsymmetrical diarylpalladium complex trans-Pd(C6F5)(2,4,6-C6F3H2)(PEt3)2, derived from transmetallation between 2,4,6-trifluorophenylboronic acid and trans-Pd(C6F5)I(PEt3)2
The reactions of 2,4,6-trifluorophenylboronic acid with aryl(iodo)palladium(II) complexes, trans-Pd(C6F5)I(PR3)2
(PR3
= PEt3, PMe2Ph, PMePh2) in the presence of Ag2O afforded trans-Pd(C6F5)(2,4,6-C6F3H2)(PR3)2 which are stabilized by fluorine atoms in the ortho positions.
Electrochemical Synthesis of Biaryls via Oxidative Intramolecular Coupling of Tetra(hetero)arylborates
作者:Arif Music、Andreas N. Baumann、Philipp Spieß、Allan Plantefol、Thomas C. Jagau、Dorian Didier
DOI:10.1021/jacs.9b12300
日期:2020.3.4
scope, scalability and robustness of this unconventional catalyst-free transformation, leading to functional-ized biaryls and ultimately furnishing drug-like small molecules as well as late stage derivatization of natural compounds. In addition, the observed selectivity of the oxidative coupling reaction is related to the electronic structure of the TABs through quantum-chemical calculations and experimental