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.
Pd-Catalyzed Decarboxylative Cross Coupling of Potassium Polyfluorobenzoates with Aryl Bromides, Chlorides, and Triflates
作者:Rui Shang、Qing Xu、Yuan-Ye Jiang、Yan Wang、Lei Liu
DOI:10.1021/ol100008q
日期:2010.3.5
Pd-catalyzed decarboxylative cross coupling of potassiumpolyfluorobenzoates with arylbromides, chlorides, and triflates is achieved by using diglyme as the solvent. The reaction is useful for synthesis of polyfluorobiaryls from readily accessible and nonvolatile polyfluorobenzoate salts. Unlike the Cu-catalyzed decarboxylation cross coupling where oxidative addition is the rate-limiting step, in
Highly efficient heterogeneous copper-catalyzed decarboxylative cross-coupling of potassium polyfluorobenzoates with aryl halides leading to polyfluorobiaryls
作者:Yang Lin、Mingzhong Cai、Zhiqiang Fang、Hong Zhao
DOI:10.1039/c7ra05711c
日期:——
reaction of potassium polyfluorobenzoates with aryl iodides and bromides was achieved in diglyme or DMAc at 130 or 160 °C in the presence of 10–20 mol% of a 1,10-phenanthroline-functionalized MCM-41-immobilized copper(I) complex, [MCM-41-Phen-CuI], yielding a variety of polyfluorobiaryls in good to excellent yields. This heterogeneous copper(I) complex could easily be prepared via a simple procedure
describes the chemoselective coupling of polyfluoroarenes with aryl germanes in the presence of aromatic C-I, C-Br, C-Cl, C-OTf and C-SiMe3 groups, as well as demonstrates the further downstream diversification to give richly functionalized and highly fluorinated polyarenes. The strategy relies on an in situ Umpolung of the FnArH, followed by selective Au(I)/Au(III)-catalyzed coupling with electron-poor or