- Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
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An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
- Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
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supporting information
p. 17887 - 17896
(2020/08/19)
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- Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
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Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
- Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
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supporting information
p. 6755 - 6764
(2019/05/06)
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- Copper-Catalyzed Regioselective C-H Sulfonyloxylation of Electron-Rich Arenes with p-Toluenesulfonic Acid and Sulfonyloxylation of Aryl(mesityl)iodonium Sulfonates
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Copper-catalyzed regioselective C-H sulfonyloxylation of electron-rich arenes with p-toluenesulfonic acid has been developed. Electron-rich benzene derivatives and heteroarenes can undergo this C-H sulfonyloxylation reaction to generate aryl tosylates. Furthermore, sulfonyloxylation of aryl(mesityl)iodonium sulfonates has also been investigated. Both aryl(mesityl)iodonium tosylates and triflates can react smoothly to get aryl sulfonates. The formed aryl sulfonates can be converted to phenols, as well as used as good partners of cross-coupling reactions.
- Huang, He,Wu, Yang,Zhang, Wen,Feng, Chun,Wang, Bi-Qin,Cai, Wan-Fei,Hu, Ping,Zhao, Ke-Qing,Xiang, Shi-Kai
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p. 3094 - 3101
(2017/03/23)
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- Para-Selective C-H Amidation of Simple Arenes with Nitriles
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A para-selective C-H amidation of simple arenes with nitriles has been developed. By increasing the amount of arenes, a further meta-selective C-H arylation of the produced amides occurred. Both steric and electronic effects are utilized to control the selectivity, resulting in only para-selective amidation products. The readily available nitriles as amidation reagents instead of amides makes the synthesis of N-arylamides more accessible.
- Xiang, Shi-Kai,Li, Jin-Mei,Huang, He,Feng, Chun,Ni, Hai-Liang,Chen, Xiao-Zhen,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Redshaw, Carl
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p. 3435 - 3440
(2016/01/25)
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