720-43-4Relevant academic research and scientific papers
FLUORINATING AGENT AND METHOD FOR PRODUCING FLUORINE-CONTAINING COMPOUNDS
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Paragraph 0114; 0116; 0141-0142; 0145-0148, (2022/04/06)
The present invention provides the compound represented in general formula (A1) [Ar1 is a C6-14 aryl group or a C5-14 nitrogen-containing heteroaryl group, substituted with at least two electron-attracting groups; R1 is a C1-30 alkyl group, a C6-14 aryl group, or a C5-14 nitrogen-containing heteroaryl group; the electron-attracting group is a halogen atom, a trihalomethyl group, a cyano group, a nitro group, -CO2R or -CO2N(R)2 (the Rs independently represent C1-30 alkyl groups)].
Organo-catalyzed Michael addition of 2-fluoro-2-arylacetonitriles
Chen, De-Yin,Song, Shuai,Chen, Ling-Yan,Ren, Xinfeng,Li, Ya
supporting information, (2021/03/01)
An efficient synthesis of a variety of 2-arylacetonitriles containing a fluorinated stereogenic center through organo-catalyzed Michael addition reaction of 2-fluoro-2-arylacetonitriles has been developed. This protocol uses a cheap organocatalyst (DBU) and has a broad substrate scope: α, β-unsaturated ketones, esters, nitriles and sulfones were all successfully reacted. Importantly, water proved to be a good solvent for this reaction.
Bench-Stable Electrophilic Fluorinating Reagents for Highly Selective Mono- and Difluorination of Silyl Enol Ethers
Adachi, Akiya,Aikawa, Kohsuke,Ishibashi, Yuichiro,Nozaki, Kyoko,Okazoe, Takashi
supporting information, p. 11919 - 11925 (2021/07/02)
Efficient methods for the synthesis of fluorinated compounds have been intensively studied, recently. Development of practical fluorinating reagents is indispensable for this purpose. Herein, bench-stable electrophilic fluorinating reagents were synthesized as N-fluorobenzenesulfonimide (NFSI) substitutes. Reagents obtained by replacing one of the NFSI sulfonyl groups with an acyl group led to the highly selective monofluorination of silyl enol ethers with suppression of undesired overreaction, that is, difluorination. On the other hand, reagents bearing electron-withdrawing substituents at NFSI benzenesulfonyl groups efficiently facilitated the difluorination of silyl enol ethers under base-free conditions. Thus, both mono- and difluorinated target materials were prepared from the same substrate.
Iridium-Catalyzed Asymmetric Hydrogenation of α-Fluoro Ketones via a Dynamic Kinetic Resolution Strategy
Tan, Xuefeng,Wen, Jialin,Zeng, Weijun,Zhang, Xumu
supporting information, p. 7230 - 7233 (2020/10/02)
The discrimination of a fluorine atom from a hydrogen atom has been challenging in asymmetric catalysis. We herein report iridium-catalyzed hydrogenation of α-fluoro ketones using a strategy of dynamic kinetic resolution. Both enantiomeric and diastereomeric selectivities were satisfactory in the preparation of β-fluoro alcohols. The DFT calculation revealed a C-F···Na charge-dipole interaction in the transition state of hydride transfer. This noncovalent interaction would be responsible for the diastereomeric control.
Preparation method of monofluorobromoacetone derivative
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Paragraph 0025-0033, (2020/06/16)
The invention relates to a preparation method of a monofluorobromoacetone derivative. The method comprises the following steps: mixing a compound as shown in a formula (1) with a catalyst, a ligand, alkali and a solvent, performing reacting with a compound as shown in a formula (2) under the protection of N2 until the reaction is complete, extracting and separating the obtained reaction solution to obtain the monofluorobromoacetone derivative as shown in a formula (3), wherein R1 is phenyl, substituted phenyl or heterocyclic ring; R2 is phenyl or substituted phenyl. Compared with the prior art, the method has the advantages of high reaction selectivity, milder conditions and shorter reaction time.
A synthesis method of [...] acetone derivatives
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, (2019/06/30)
The invention provides a method for synthesizing [...] acetone derivatives, characterized in that includes: formula (IV) is shown in the compounds are dissolved in 1, 4 - dioxane (dioxane) in, adding catalyst trifluoromethanesulfonic acid nickel (II) (Ni
Nickel-Catalyzed Coupling Reaction of α-Bromo-α-fluoroketones with Arylboronic Acids toward the Synthesis of α-Fluoroketones
Liang, Junqing,Han, Jie,Wu, Jingjing,Wu, Pingjie,Hu, Jian,Hu, Feng,Wu, Fanhong
, p. 6844 - 6849 (2019/09/07)
A nickel-catalyzed coupling reaction of α-bromo-α-fluoroketones with arylboronic acids was reported, which provides an efficient pathway to access 2-fluoro-1,2-diarylethanones in high yields. We also disclosed the synthesis of the monofluorination agents
Kinetics of Electrophilic Fluorinations of Enamines and Carbanions: Comparison of the Fluorinating Power of N-F Reagents
Timofeeva, Daria S.,Ofial, Armin R.,Mayr, Herbert
, p. 11474 - 11486 (2018/09/13)
Kinetics of the reactions of enamines and carbanions with commonly used fluorinating reagents, N-fluorobenzenesulfonimide (NFSI), N-fluoropyridinium salts, Selectfluor, and an N-fluorinated cinchona alkaloid, have been investigated in acetonitrile. The reactions follow second-order kinetics, and from the measured rate constants one can derive that the fluorinations proceed via direct attack of the nucleophiles at fluorine, not by SET processes. Correlations of the fluorination rates with the pKaH values of the nucleofugal leaving groups and the calculated fluorine plus detachment energies are discussed. The rate constants for the reactions with deoxybenzoin-derived enamines follow the linear free energy relationship log k2(20 °C) = sN(N + E) which allows the empirical electrophilicity parameters E for these fluorinating agents to be derived from the measured rate constants and the tabulated N and sN parameters for the nucleophiles. Though the deviations of the measured rate constants from those calculated by this relationship are larger than for reactions of Csp2-centered electrophiles with nucleophiles, it is shown that the electrophilicity parameters E reported in this work are able to rationalize known fluorination reactions and are, therefore, recommended as guide for designing new electrophilic fluorinations.
Lewis acid-mediated defluorinative [3+2] cycloaddition/aromatization cascade of 2,2-difluoroethanol systems with nitriles
Hsieh, Min-Tsang,Lee, Kuo-Hsiung,Kuo, Sheng-Chu,Lin, Hui-Chang
, p. 1605 - 1610 (2018/03/05)
The properties of C?F bonds, including high thermal and chemical stability, make derivatization of organic fluorine-containing compounds by the activation of the C?F bond and subsequent functionalization quite challenging. We herein report a Lewis acid-mediated defluorinative cycloaddition/aromatization cascade of 2,2-difluoroethanols with nitriles as a novel synthetic method for the preparation of 2,4,5-trisubstituted oxazoles. This reaction, which involves cleavage of two C?F bonds and the consecutive formation of C?O and C?N bonds in a one-pot fashion, features a broad substrate scope and moderate to high reaction yields. Mechanistic studies revealed that the reaction is initiated by the Lewis acid-mediated ring closure of the 2,2-difluoroethanol to produce the fluoroepoxide intermediate. (Figure presented.).
Α - fluoro acetophenone derivative
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Paragraph 0029; 0040; 0047-0049, (2018/08/28)
PROBLEM TO BE SOLVED: To provide a new production method of an α-fluoroacetophenone derivative by a simple one-step fluorination reaction with an acetophenone derivative under a mild condition.SOLUTION: An acetophenone derivative represented by formula (I) is reacted with a hydrogen fluoride/amine complex in the presence of a hypervalent iodine compound, (in the formula, a ring A indicates an aromatic ring of 1-3 members; Rindicates a hydrogen atom or an aromatic ring of 1-3 members that may be substituted; Rindicates a hydrogen atom or an alkyl group of 1-6 carbons; and Rindicates a hydrogen atom, an alkyl group of 1-6 carbons, an alkoxy group of 1-6 carbons or a halogen atom). The H part in formula (I) is substituted and fluorinated.
