73789-98-7Relevant academic research and scientific papers
Direct Approach to 3-Fluoroindoles and 3,3-Difluoroindolines from 2,2-Difluoro-2-phenylethan-1-amines via C-H/N-H Coupling
Zhang, Lanfei,Zhang, Xiaofei,Cui, Yongmei,Yang, Chunhao
supporting information, p. 3815 - 3826 (2021/06/28)
Herein, a direct method for the synthesis of 3-fluoroindoles and 3,3-difluoroindolines from easily accessible 2,2-difluoro-2-phenyl ethan-1-amines is presented. This protocol was performed by Pd-catalyzed direct C-H/N-H coupling and employed picolinamide as a directing group. By controlling the temperature for this transformation, various 3,3-difluoroindolines and 3-fluoroindoles could be isolated with moderate to good yields.
Access to α,α-Difluoro-γ-amino Acids by Nickel-Catalyzed Reductive Aryldifluoroacetylation of N -Vinylacetamide
Zhao, Qing-Wei,Yang, Zhi-Fang,Fu, Xia-Ping,Zhang, Xingang
supporting information, p. 1565 - 1569 (2020/11/16)
A nickel-catalyzed reductive aryldifluoroacetylation of N -vinylacetamide with ethyl chloro(difluoro)acetate and aryl iodides is described. This chelating amide carbonyl group-assisted strategy provides rapid access to a variety of protected α,α-difluoro-γ-amino acids that might have potential applications in peptide chemistry and protein engineering. An advantage of this method is its synthetic simplicity, with no preparation of organometallic reagents.
Nickel-catalyzed carbodifunctionalization of: N -vinylamides enables access to γ-amino acids
Yang, Zhi-Fang,Xu, Chang,Zheng, Xing,Zhang, Xingang
supporting information, p. 2642 - 2645 (2020/03/10)
A nickel-catalyzed tandem reaction of N-vinylamides with arylboronic acids and bromodifluoroacetate has been developed. The use of amide carbonyl as a chelating group efficiently furnishes a series of protected α,α-difluoro-γ-amino acid esters. The reaction can also extend to bromoacetate and 2-bromomalonate. The advantages of this protocol are high functional group tolerance and a broad substrate scope, including a variety of N-vinylamides. In particular, the use of removable amide carbonyl groups provides potential opportunities for applications in peptide chemistry and protein engineering.
Synthetic method of aromatic ring group or aromatic heterocyclic tetrazole
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Paragraph 0036-0042; 0047, (2020/12/30)
The synthetic method comprises the following steps: (1) reacting 1.0 eq of ArI or HArI with 1.2 eq of ethyl 2, 2-difluoroacetate in the presence of DMSO as a solvent and 4.0 eq of Cu under the protection of nitrogen at 30 DEG C and 50 DEG C, and purifying to obtain a first intermediate compound; (2) dissolving 1.0 eq of the first intermediate compound in a mixed solvent of THF and water, adding 2.0 eq of LiOH, reacting at room temperature for 2 hours, spin-drying the solvent, adding HCl until the pH value is equal to 3, and filtering to obtain a second intermediate compound; and (3) reacting 1.0 eq of the second intermediate compound with 2.0 eq of diphenyl azide phosphate in the presence of 2.5 eq of triethylamine by taking tert-butyl alcohol as a solvent to generate aromatic ring group or aromatic heterocyclic tetrazole. The invention provides a novel synthetic method of aromatic ring group or aromatic heterocyclic tetrazole, wherein a target compound can be more conveniently obtained, and reagents participating in the reaction are low in toxicity, mild in reaction condition, simple and safe in aftertreatment, good in product quality and suitable for large-scale production.
trans-Selective Aryldifluoroalkylation of Endocyclic Enecarbamates and Enamides by Nickel Catalysis
Cheng, Ran,Luo, Yun-Cheng,Wang, Ming-Kuan,Xu, Chang,Zhang, Xingang
supporting information, p. 18741 - 18747 (2020/08/26)
Efficient methods for the dicarbofuntionalization of the cyclic alkenes 2-pyrroline and 2-azetine are limited. Particularly, the dicarbofunctionalization of endocyclic enecarbamates to achieve fluorinated compounds remains an unsolved issue. Reported here is a nickel-catalyzed trans-selective dicarbofunctionalization of N-Boc-2-pyrroline and N-Boc-2-azetine, a class of endocyclic enecarbamates previously unexplored for transition metal catalyzed dicarbofunctionalization. The reaction can be extended to six- and seven-membered endocyclic enamides. A variety of arylzinc reagents and bromodifluoroacetate, and its derivatives, undergo the reaction, providing straightforward and efficient access to an array of pyrrolidine- and azetidine-containing fluorinated amino acids and oligopeptides, which may have applications in the life sciences.
Silver-Catalyzed Decarboxylative Radical Addition/Cyclization of α,α-Difluoroarylacetic Acids with Acrylamides To Synthesize Difluorinated Oxindoles
Li, Yin-Long,Wang, Ji-Bo,Wang, Xue-Lin,Cao, Yang,Deng, Jun
supporting information, p. 6052 - 6059 (2017/11/14)
A facile silver-catalyzed decarboxylative radical addition/cyclization reaction of α,α-difluoroarylacetic acids and acrylamides has been disclosed. The method provides a highly attractive approach to synthesize a series of difluorinated oxindoles that contain various functional groups in moderate to good yields under mild conditions. Moreover, experimental studies reveal that the CF2 group of the α,α-difluoroarylacetic acids plays a vital role in the transformation.
Palladium-Catalyzed Cross-Coupling of Ethyl Bromodifluoroacetate with Aryl Bromides or Triflates and Cross-Coupling of Ethyl Bromofluoroacetate with Aryl Iodides
Xia, Tingting,He, Lei,Liu, Yahu A.,Hartwig, John F.,Liao, Xuebin
supporting information, p. 2610 - 2613 (2017/05/24)
A palladium-catalyzed Negishi cross-coupling reaction of ethyl bromodifluoroacetate with aryl bromides or aryl triflates to construct C(sp2)-CF2 bonds is described. The reaction was conducted under mild reaction conditions, and no preparation of organozinc reagents is required. This is the first report encompassing the conversion of aryl triflates into products containing C-CF2 bonds. In addition, the construction of C(sp2)-CHF bonds was achieved under mild conditions via a cross-coupling of aryl iodides with ethyl bromofluoroacetate.
Carbonylation of Difluoroalkyl Bromides Catalyzed by Palladium
Zhao, Hai-Yang,Feng, Zhang,Luo, Zhiji,Zhang, Xingang
supporting information, p. 10401 - 10405 (2016/08/24)
Although important progress has been made in the fluoroalkylation reactions, the transition-metal-catalyzed carbonylative fluoroalkylation reaction remains challenging so far. Herein, we report the first example of a Pd-catalyzed carbonylation of difluoroalkyl bromides with (hetero)arylboronic acids under one atmosphere pressure of CO. The reaction can also be extended to the aryl potassium trifluoroborate salts. The advantages of this protocol are synthetic simplicity, broad substrate scope, and excellent functional group compatibility. The resulting difluoroalkyl ketones can serve as versatile building blocks for the synthesis of various useful fluorinated compounds.
Access to Difluoromethylated Arenes by Pd-Catalyzed Reaction of Arylboronic Acids with Bromodifluoroacetate
Feng, Zhang,Min, Qiao-Qiao,Zhang, Xingang
supporting information, p. 44 - 47 (2016/01/15)
An unprecedented example of Pd-catalyzed difluoromethylation of aryl boronic acids with bromodifluoroacetate is described. The reaction proceeds under mild reaction conditions with hydroquinone and Fe(acac)3 as additives. Preliminary mechanistic studies reveal that a difluorocarbene pathway is involved in the reaction, which is unusual compared to the most traditional approaches. This reaction has advantages of high efficiency and excellent functional group compatibility, even toward bromide and hydroxy group, thus providing a useful protocol for drug discovery and development.
Silver-catalyzed oxidative decarboxylation of difluoroacetates: Efficient access to C-CF2 bond formation
Wan, Wen,Ma, Guobin,Li, Jialiang,Chen, Yunrong,Hu, Qingyang,Li, Minjie,Jiang, Haizhen,Deng, Hongmei,Hao, Jian
, p. 1598 - 1601 (2016/01/30)
A mild, versatile and efficient method for the silver(i)-catalyzed oxidative decarboxylative gem-difluoromethylenation has been developed. The radical cascade reaction comprises the addition of an oxidatively generated difluoromethylene radical to the isonitrile functionality and subsequent homolytic aromatic substitution. It provides a novel and efficient access to the C-CF2 bond formation.
