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.
Palladium-catalyzed decarbonylative and decarboxylative cross-coupling of acyl chlorides with potassium perfluorobenzoates affording unsymmetrical biaryls
作者:Liyan Fu、Jingwen You、Yasushi Nishihara
DOI:10.1039/d1cc00202c
日期:——
describes the synthesis of unsymmetrical biaryls by the palladium-catalyzed cross-coupling reaction of acylchlorides with potassium perfluorobenzoates. This transformation is unique in that it involves simultaneous decarbonylation and decarboxylation under redox-neutral conditions. Compared to conventional cross-coupling protocols for the synthesis of unsymmetrical biaryls, the two reactants in this synthetic
Direct palladium-catalyzed desulfitative CC coupling of polyfluoroarenes with arylsulfinate salts: Water-accelerated reactions
作者:Xiaoxi Lin、Yi You、Zhiqiang Weng
DOI:10.1016/j.jfluchem.2014.06.017
日期:2014.9
A newapproach to the synthesis of fluorinated biaryl compounds from easily available starting materials is described. This protocol is based on the direct palladium-catalyzed desulfitative cross-coupling of polyfluoroarenes with various arylsulfinate salts via CH bond activation, accelerated by trace amount of water. The method allows the synthesis of various fluorinated biaryl products in moderate
Palladium-Catalyzed Olefination and Arylation of Polyfluoroarenes Using Molecular Oxygen as the Sole Oxidant
作者:Qiufeng Huang、Xinyu Zhang、Lin Qiu、Jiajun Wu、Hanbing Xiao、Xiaofeng Zhang、Shen Lin
DOI:10.1002/adsc.201500632
日期:2015.11.16
The palladium-catalyzed cross-dehydrogenative-coupling of polyfluoroarenes with alkenes or simple arenes has been developed. The approach is characterized by using atmospheric pressure of molecularoxygen as the sole oxidant, and provides a straightforward and environmentally benign route to functionalized polyfluoroarenes.
Abstract A Pd-catalyzed decarboxylativecoupling of substituted benzoic acids with phenylboronic acid has been developed. Under the optimized conditions, a variety of substituted benzoic acids were found to undergo decarboxylativecoupling with various phenylboronic acids to give the desired unsymmetrical biaryls in good yields. [Supplementary materials are available for this article. Go to the publisher's