179990-93-3Relevant academic research and scientific papers
Electrochemical-Promoted Nickel-Catalyzed Oxidative Fluoroalkylation of Aryl Iodides
Zou, Zhenlei,Li, Heyin,Huang, Mengjun,Zhang, Weigang,Zhi, Sanjun,Wang, Yi,Pan, Yi
supporting information, p. 8252 - 8256 (2021/11/01)
This work describes a general strategy for metal-catalyzed cross-coupling of fluoroalkyl radicals with aryl halides under electrochemical conditions. The contradiction between anodic oxidation of fluoroalkyl sulfinates and cathodic reduction of low-valent nickel catalysts can be well addressed by paired electrolysis, allowing for direct introduction of fluorinated functionalities into aromatic systems.
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.
Controlling the cleavage of carbon-carbon bonds to generate α,α-difluorobenzyl carbanions for the construction of difluoromethylbenzenes
Khatri, Hari R.,Han, Changho,Luong, Erica,Pan, Xiaoliang,Adam, Amna T.,Alshammari, Maali D.,Shao, Yihan,Colby, David A.
, p. 11665 - 11675 (2019/10/02)
Controlling the cleavage of carbon-carbon bonds during a chemical reaction is a substantial challenge; however, synthetic methods that accomplish this objective produce valuable and often unexplored reactivity. We have designed a mild process to generate α,α-difluorobenzyl carbanions in the presence of potassium carbonate by exploiting the cleavage of C-C bonds during the release of trifluoroacetate. The initiating reagent is potassium carbonate, which represents an improvement over existing protocols that require a strong base. Fragmentation studies across substituted arenes and heteroarenes were conducted along with computational analyses to elucidate reactivity trends. Furthermore, the mildly generated α,α-difluorobenzyl carbanions from electron-deficient aromatics and heteroaromatic rings can react with aldehydes to create derivatives of difluoromethylbenzenes, which are valuable synthetic targets.
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 (2019/11/05)
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.
A fluorine-containing methyl compounds and its preparation method (by machine translation)
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Paragraph 0182; 0183; 0189; 0190; 0191; 0192; 0215-0218, (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)
Palladium-Catalyzed Decarbonylative Difluoromethylation of Acid Chlorides at Room Temperature
Pan, Fei,Boursalian, Gregory B.,Ritter, Tobias
supporting information, p. 16871 - 16876 (2018/11/23)
Methods for the direct synthesis of difluoromethylated arenes are sparse, despite the importance of the difluoromethyl group in medical, agro-, and materials chemistry. A palladium-catalyzed decarbonylative cross-coupling reaction of acid chlorides with a difluoromethyl zinc reagent is achieved to access difluoromethylated compounds. The transformation proceeds at room temperature and shows broad functional group tolerance, thus providing a general and efficient method for decarbonylative difluoromethylation of a wide range of aromatic carboxylic acids.
Method for preparing alpha-aryl/heteroaryl/alkenyl-alpha,alpha-difluoromethyl compounds
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Paragraph 0141; 0142; 0143; 0150; 0151; 0152; 0192; 0193, (2018/09/08)
The invention discloses a method for preparing alpha-aryl/heteroaryl/alkenyl-alpha,alpha-difluoromethyl compounds. The preparation method for the alpha-aryl/heteroaryl/alkenyl-alpha,alpha-difluoromethyl compounds as shown in a formula C which is described
Nickel-Catalyzed Difluoromethylation of Arylboronic Acids with Bromodifluoromethane
Fu, Xia-Ping,Xiao, Yu-Lan,Zhang, Xingang
supporting information, p. 143 - 146 (2018/01/05)
Although bromodifluoromethane (BrCF2H) is a simple and readily available fluorine source, direct formation of difluoromethylated arenes with BrCF2H has not been reported. Herein, we describe an efficient method to access difluoromethylated arenes through a nickel-catalyzed difluoromethylation of arylboronic acids with BrCF2H. The reaction exhibits high efficiency, good functional group tolerance and broad substrate scope, thus providing an efficient route for applications in drug discovery and development. Preliminary mechanistic studies reveal that a difluoromethyl radical is involved in the reaction.
Chlorodifluoromethane-triggered formation of difluoromethylated arenes catalysed by palladium
Feng, Zhang,Min, Qiao-Qiao,Fu, Xia-Ping,An, Lun,Zhang, Xingang
, p. 918 - 923 (2017/09/01)
Difluoromethylated aromatic compounds are of increasing importance in pharmaceuticals, agrochemicals and materials. Chlorodifluoromethane (ClCF2H), an inexpensive, abundant and widely used industrial raw material, represents the ideal and most straightforward difluoromethylating reagent, but introduction of the difluoromethyl group (CF2H) from ClCF2H into aromatics has not been reported. Here, we describe a direct palladium-catalysed difluoromethylation method for coupling ClCF2H with arylboronic acids and esters to generate difluoromethylated arenes with high efficiency. The reaction exhibits a remarkably broad substrate scope, including heteroarylboronic acids, and was used for difluoromethylation of a range of pharmaceuticals and biologically active compounds. Preliminary mechanistic studies revealed that a palladium difluorocarbene intermediate is involved in the reaction. Although numerous metal-difluorocarbene complexes have been prepared, the catalytic synthesis of difluoromethylated or difluoromethylenated compounds involving metal-difluorocarbene complexes has not received much attention. This new reaction therefore also opens the door to understand metal- difluorocarbene complex catalysed reactions.
Synthesis, reactivity, and catalytic applications of isolable (NHC)Cu(CHF2) complexes
Bour, James R.,Kariofillis, Stavros K.,Sanford, Melanie S.
supporting information, p. 1220 - 1223 (2017/05/29)
Difluoromethyl copper complexes have been proposed as key intermediates in a variety of Cu-catalyzed difluoromethylation reactions. However, studies of these putative intermediates have been impeded by the low stability of these [Cu(CHF2)] species. This report describes the synthesis of isolable N-heterocyclic carbene ligated copper(I) difluoromethyl complexes. The stoichiometric reactions of these complexes with aryl electrophiles (i.e., diaryliodonium salts, aryl iodides, and aryl bromides) are described. In addition, Nheterocyclic carbene copper(I) species are demonstrated to serve as catalysts for the cross-coupling of aryl iodides with (difluoromethyl)trimethylsilane to afford difluoromethyl arene products.
