343957-95-9Relevant articles and documents
Controllable catalytic difluorocarbene transfer enables access to diversified fluoroalkylated arenes
Fu, Xia-Ping,Xue, Xiao-Song,Zhang, Xue-Ying,Xiao, Yu-Lan,Zhang, Shu,Guo, Yin-Long,Leng, Xuebing,Houk, Kendall N.,Zhang, Xingang
, p. 948 - 956 (2019)
Difluorocarbene has important applications in pharmaceuticals, agrochemicals and materials, but all these applications proceed using just a few types of reaction by taking advantage of its intrinsic electrophilicity. Here, we report a palladium-catalysed strategy that confers the formed palladium difluorocarbene (Pd=CF2) species with both nucleophilicity and electrophilicity by switching the valence state of the palladium centre (Pd(0) and Pd(ii), respectively). Controllable catalytic difluorocarbene transfer occurs between readily available arylboronic acids and the difluorocarbene precursor diethyl bromodifluoromethylphosphonate (BrCF2PO(OEt)2). From just this simple fluorine source, difluorocarbene transfer enables access to four types of product: difluoromethylated and tetrafluoroethylated arenes and their corresponding fluoroalkylated ketones. The transfer can also be applied to the modification of pharmaceuticals and agrochemicals as well as the one-pot diversified synthesis of fluorinated compounds. Mechanistic and computational studies consistently reveal that competition between nucleophilic and electrophilic palladium difluorocarbene ([Pd]=CF2) is the key factor controlling the catalytic difluorocarbene transfer.
Precatalyst Effects on Pd-Catalyzed Cross-Coupling Difluoromethylation of Aryl Boronic Acids
Hori, Kaishi,Motohashi, Hirotaka,Saito, Daichi,Mikami, Koichi
, p. 417 - 421 (2019/01/11)
The Pd-catalyzed difluoromethylation of aryl boronic acids with difluoroiodomethane is shown to provide the difluoromethyl compounds in high to moderate yields by Pd(PPh3)2/DPEphos catalyst in H2O/toluene. Mechanistic studies show that the oxidative addition by Pd(PPh3)4 rather than Pd2(dba)3 precatalyst to difluoroiodomethane provides a square-planar trans-(PPh3)2Pd(II)(CF2H)I complex defined by X-ray crystallographic analysis. The trans-(PPh3)2Pd(CF2H)I complex is transformed to cis-(PPh3)2Pd(CF2H)Ph detected by low temperature NMR analysis, via transmetalation with phenylboronic acids. The reductive elimination occurs via ligand exchange to DPEphosPd(CF2H)Ph to give Ph-CF2H (t1/2 = 144.7 min at 20 °C) with formation of the Pd(0)(PPh3)2/DPEphos catalyst.
A fluorine-containing methyl compounds and its preparation method (by machine translation)
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Paragraph 0179; 0180; 0185; 0186; 0187; 0188; 0224-0227, (2019/05/11)
The invention discloses a fluorine-containing methyl compounds and its preparation method. The invention provides a fluorine-containing shown as formula C methyl compounds, wherein R is aryl group containing, or, containing a hetero aryl group, and the aryl group or the heteroaryl on the aromatic carbon atom and CFm Hn Connected, m is 1 or 2, m + n=3. The compounds according to the prior art is difficult to make, the preparation method of the raw material and the catalyst are the ordinary industrial raw materials, cheap and easy to obtain, high reaction efficiency, high yield, after treatment is simple, low toxicity, environmental protection, functional group compatibility is good, broad-spectrum is strong, the production cost is low, it has very good market application prospect. (by machine translation)
