454-31-9Relevant articles and documents
Tandem Difluoroalkylation-Arylation of Enamides Catalyzed by Nickel
Gu, Ji -Wei,Min, Qiao -Qiao,Yu, Ling -Chao,Zhang, Xingang
, p. 12270 - 12274 (2016)
A nickel-catalyzed three-component reaction for the synthesis of difluoroalkylated compounds through tandem difluoroalkylation-arylation of enamides has been developed. The reaction tolerates a variety of arylboronic acids and widely available difluoroalkyl bromides, and even the relatively inert substrate chlorodifluoroacetate. The significant advantages of this protocol are the low-cost nickel catalyst, synthetic convenience, excellent functional-group compatibility and high reaction efficiency.
Photoluminescence of Seven-Coordinate Zirconium and Hafnium Complexes with 2,2′-Pyridylpyrrolide Ligands
Zhang, Yu,Akhmedov, Novruz G.,Petersen, Jeffrey L.,Milsmann, Carsten
, p. 3042 - 3052 (2019)
Luminescent seven-coordinated zirconium and hafnium complexes bearing three mono-anionic 2,2′-pyridylpyrrolide ligands and one chloride were synthesized. Solid-state structures and the dynamic behaviors in solution were probed by X-ray crystallography and variable temperature 1H NMR experiments, respectively. Absorption spectroscopy and time-dependent density functional theory (TD-DFT) calculations supported a hybrid of ligand-to-metal charge transfer (LMCT)/ligand-to-ligand charge transfer (LLCT) for the visible light absorption band. The complexes (MePMPMe)3MCl (M=Zr, Hf, MePMPMe=3,5-dimethyl-2-(2-pyridyl)pyrrolide) are emissive in solution at room temperature upon irradiation with visible light due to a combination of phosphorescence and fluorescence characterized by excited state lifetimes in the μs and low to sub-ns timescale, respectively. Electrochemical experiments revealed that the zirconium complex possesses a reversible redox event under highly reducing condition (?2.29 V vs. Fc+/0).
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.
Diethylzinc-Mediated Radical 1,2-Addition of Alkenes and Alkynes
Li, Xin,He, Songtao,Song, Qiuling
supporting information, p. 2994 - 2999 (2021/05/04)
A novel diethylzinc-mediated radical 1,2-addition of perfluoroalkyl iodides to unactivated alkenes and alkynes is presented, which demonstrates a novel way to generate an ethyl difluoroacetate radical. This method is highly efficient and gives full conversions of the substrates, high yields of the products, and negligible byproducts and requires no column chromatography purifications. The mild conditions enable this protocol to exhibit excellent functional group compatibility.
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.
Method for co-producing 2-fluoropropionate and ethyl difluoroacetate
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Paragraph 0035; 0037; 0038; 0040; 0041; 0043; 0044; 0046, (2019/05/04)
The invention discloses a method for co-producing 2-fluoropropionate and ethyl difluoroacetate. The method comprises: (a) carrying out a reaction on a fluorinating reagent and a lactate for 0.5-7 h ata reaction temperature of 30-120 DEG C according to a molar ratio of 0.5-2:1, cooling the reaction material after completing the reaction, adding a nitrogen-containing compound, and carrying out pressure reducing rectification to obtain a 2-fluoropropionate product and N,N-dimethyl difluoroacetamide; and (b) adding concentrated sulfuric acid to a mixture of anhydrous ethanol and the N,N-dimethyldifluoroacetamide obtained in the step (a), carrying out a reaction for 1-10 h at a reaction temperature of 50-170 DEG C, cooling after completing the reaction, separating the liquid, and carrying outrectification to obtain the ethyl difluoroacetate product, wherein a molar ratio of anhydrous ethanol to N,N-dimethyl difluoroacetamide is 0.5-4.5:1, and a molar ratio of concentrated sulfuric acid to N,N-dimethyl difluoroacetamide is 0.1-1.5:1. According to the present invention, the method has advantages of environmental protection, high yield and low cost.
Alkene Carboarylation through Catalyst-Free, Visible Light-Mediated Smiles Rearrangement
Whalley, David M.,Duong, Hung A.,Greaney, Michael F.
, p. 1927 - 1930 (2019/01/16)
A light-mediated Truce–Smiles arylative rearrangement is described that proceeds in the absence of any photocatalyst. The protocol creates two C?C bonds from simple starting materials, with the installation of an aryl ring and a difluoroacetate moiety across unactivated alkenes. The reaction proceeds via a radical mechanism, utilizing a light-mediated reduction of ethyl bromodifluoroacetate by N,N,N′,N′-tetramethylethylenediamine (TMEDA) to set up intermolecular addition to an unactivated alkene, followed by Truce–Smiles rearrangement.
Method for preparing ethyl bromodifluoroacetate
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Paragraph 0027, (2018/04/02)
The invention provides a method for preparing ethyl bromodifluoroacetate and relates to a preparation method of a chemical reagent. The method takes trichloro ethylene as a raw material, and comprisesthe following steps: under the action of ultraviolet light of a catalytic medium, an oxidation reaction happens between trichloro ethylene and oxygen in a reactor to synthesize dichloracetyl chloride; an amination reaction happens between dichloracetyl chloride and diethylamine under the action of a catalyst to synthesize dichloroacetyl diethylamine; a fluorination reaction happens between dichloroacetyl diethylamine and anhydrous potassium fluoride under the action of a solvent and a phase transfer catalyst to synthesize difluoroacetyl diethylacetamide; difluoroacetyl diethylacetamide is esterified to synthesize ethyl difluoroacetate; and by taking cupric bromide as a brominating agent, ethyl difluoroacetate is bromized to prepare the end product (ethyl bromodifluoroacetate). The methodhas the characteristics that the equipment investment is low, reaction conditions are mild, the method is safely implemented at normal pressure, and after-treatment is simple.
A 4, 4 - difluoro-acetyl-acetic acid alkyl ester preparation method
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Paragraph 0054, (2017/08/25)
The invention discloses a method for preparing alkyl 4,4-difluoroacetylacetate. The method has the advantages of easily available raw materials, simple process flow, safety in operation and high yield. The method comprises the following steps: (1) carrying out hydrolysis reaction on 1,1,2,2-tetrafluoroethyl ether used as a raw material and water in an acid and separating to obtain ethyl difluoroacetate and hydrogen fluoride; (2) reacting ethyl difluoroacetate obtained in the step (1) and alkyl acetate in the presence of an alkaline catalyst to obtain 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt; and (3) neutralizing 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt obtained in the step (2) and hydrogen fluoride to obtain alkyl 4,4-difluoroacetylacetate.
MANUFACTURING METHOD OF ESTER COMPOUND
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Paragraph 0064-0071, (2018/01/06)
PROBLEM TO BE SOLVED: To provide a manufacturing method of an ester compound capable of recovering the ester compound at high purity and being manufactured with simple method at low cost. SOLUTION: There is provided a manufacturing method of an ester compound represented by the general formula (1): RACOORB, where RA and RB is an alkyl group, a halogenated alkyl group, an ether oxygen atom-containing alkyl group or an ether oxygen atom-containing alkyl group substituted by one or more halogen atom, and RA and RB may be same or different. It has a process A for contacting a compound represented by the general formula (2): RACF2ORB, where RA and RB are same as the formula (1), with an acid catalyst in presence of a material containing SiO2 and RBOH, where RB is same as the formula (1), so as to obtain a crude product containing the ester compound and hydrogen fluoride, and a process B for purifying the crude product by adding alkali to the crude product. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
