- The transmission of resonance effects through a methylene group-spectroscopic studies on some α-substituted-acetonitriles and p-toluonitriles
-
Frequencies and integrated intensities are recorded for the νCN mode of a representative selection of α-substituted acetonitriles, α-substituted-p-toluonitriles and β-substituted propionitriles.The frequencies of the acetonitriles are confirmed
- Butt, G.,Cilmi, J.,Hoobin, P. M.,Topsom, R. D.
-
-
Read Online
- PROCESSES FOR FLUORINATION
-
The present technology relates to fluorination reactions. Specifically, processes useful for making the fungicide compound, DFT are disclosed. More broadly, also disclosed herein are processes useful for deoxyfluorination at the α-aromatic position of a given compound.
- -
-
Paragraph 0179; 0184; 0214-0215; 0219
(2021/04/10)
-
- METHOD AND REAGENT FOR DEOXYFLUORINATION
-
A safe, simple, and selective method and reagent for deoxyfluorination is disclosed. With the method and reagent disclosed herein, organic compounds such as carboxylic acids, carboxylates, carboxylic acid anhydrides, aldehydes, and alcohols can be fluorinated by using the most common nucleophilic fluorinating reagents and electron deficient fluoroarenes as mediators under mild conditions, giving corresponding fluoroorganic compounds in excellent yield with a wide range of functional group compatibility and easy product purification. For example, directly utilizing KF for deoxyfluorination of carboxylic acids provides the most economical and the safest pathway to access acyl fluorides, key intermediates for syntheses of peptide, amide, ester, and dry fluoride salts.
- -
-
Paragraph 0148-0150; 0152; 0156
(2021/05/29)
-
- Visible-light photoredox-catalyzed selective carboxylation of C(sp3)?F bonds with CO2
-
It is highly attractive and challenging to utilize carbon dioxide (CO2), because of its inertness, as a nontoxic and sustainable C1 source in the synthesis of valuable compounds. Here, we report a novel selective carboxylation of C(sp3)?F bonds with CO2 via visible-light photoredox catalysis. A variety of mono-, di-, and trifluoroalkylarenes as well as α,α-difluorocarboxylic esters and amides undergo such reactions to give important aryl acetic acids and α-fluorocarboxylic acids, including several drugs and analogs, under mild conditions. Notably, mechanistic studies and DFT calculations demonstrate the dual role of CO2 as an electron carrier and electrophile during this transformation. The fluorinated substrates would undergo single-electron reduction by electron-rich CO2 radical anions, which are generated in situ from CO2 via sequential hydride-transfer reduction and hydrogen-atom-transfer processes. We anticipate our finding to be a starting point for more challenging CO2 utilization with inert substrates, including lignin and other biomass.
- Bo, Zhi-Yu,Chen, Lin,Gao, Tian-Yu,Jing, Ke,Lan, Yu,Liu, Shi-Han,Luo, Shu-Ping,Yan, Si-Shun,Yu, Bo,Yu, Da-Gang
-
supporting information
p. 3099 - 3113
(2021/11/16)
-
- Electrochemical-Promoted Nickel-Catalyzed Oxidative Fluoroalkylation of Aryl Iodides
-
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.
- Zou, Zhenlei,Li, Heyin,Huang, Mengjun,Zhang, Weigang,Zhi, Sanjun,Wang, Yi,Pan, Yi
-
supporting information
p. 8252 - 8256
(2021/11/01)
-
- Deoxyfluorination of alcohols with aryl fluorosulfonates
-
Aryl fluorosulfonates are developed as a deoxyfluorinating reagent in the transformation of primary and secondary alcohols into the corresponding alkyl fluorides. These reagents feature easy availability, low-cost, high stability and high efficiency. Diverse functionalities including aldehyde, ketone, ester, halogen, nitro, alkene, and alkyne are well tolerated under mild reaction conditions.
- Fei, Zhongbo,Hu, Jinbo,Li, Wei,Liu, Qinghe,Ni, Chuanfa,Wang, Xiu,Zhou, Min
-
supporting information
p. 8170 - 8173
(2021/08/23)
-
- Organophotoredox Hydrodefluorination of Trifluoromethylarenes with Translational Applicability to Drug Discovery
-
Molecular editing such as insertion, deletion, and single atom exchange in highly functionalized compounds is an aspirational goal for all chemists. Here, we disclose a photoredox protocol for the replacement of a single fluorine atom with hydrogen in electron-deficient trifluoromethylarenes including complex drug molecules. A robustness screening experiment shows that this reductive defluorination tolerates a range of functional groups and heterocycles commonly found in bioactive molecules. Preliminary studies allude to a catalytic cycle whereby the excited state of the organophotocatalyst is reductively quenched by the hydrogen atom donor, and returned in its original oxidation state by the trifluoromethylarene.
- Sap, Jeroen B.I.,Straathof, Natan J.W.,Knauber, Thomas,Meyer, Claudio F.,Meyer, Claudio F.,Médebielle, Maurice,Buglioni, Laura,Genicot, Christophe,Trabanco, Andrés A.,No?l, Timothy,Am Ende, Christopher W.,Gouverneur, Véronique
-
supporting information
p. 9181 - 9187
(2020/07/10)
-
- PROCESSES FOR FLUORINATION
-
The present technology relates to fluorination reactions. Specifically, processes useful for making the fungicide compound, DFT are disclosed. More broadly, also disclosed herein are processes useful for deoxyfluorination at the α-aromatic position of a given compound.
- -
-
Paragraph 0188
(2020/03/05)
-
- Cobalt-Catalyzed Asymmetric Cross-Coupling Reaction of Fluorinated Secondary Benzyl Bromides with Lithium Aryl Boronates/ZnBr2
-
A cobalt-catalyzed asymmetric cross-coupling of α-bromo-α-fluorotoluene derivatives with a variety of aryl zincates derived from lithium aryl n-butyl pinacol boronates and ZnBr2 under mild reaction conditions was described. In addition to mild reaction conditions, another advantage includes the compatibility of various common functional groups such as fluoride, chloride, bromide, cyano, or ester groups. Furthermore, this protocol was successfully applied to the enantioselective synthesis of three fluorinated derivatives of biologically active compounds or drug molecules.
- Huang, Weichen,Shen, Qilong,Wan, Xiaolong
-
supporting information
p. 4327 - 4332
(2020/06/27)
-
- Nucleophilic fluorination facilitated by a CsF-CaF2 packed bed reactor in continuous flow
-
A simple to prepare, dry and handle packed bed reactor carrying CsF on CaF2, towards nucleophilic fluorinations in continuous flow, is reported. The reactor also proved adaptable for silyl-ether deprotection and trifluoromethylations with Ruppert's reagent. The study includes reactor stability and scale-up investigations.
- Johansen,Lindhardt
-
supporting information
p. 825 - 828
(2018/02/06)
-
- Monofluoroalkyl-containing compound and its preparation method and use
-
The invention discloses a monofluoroalkyl-containing compound and its preparation method. The preparation method comprises that in a solvent, in the presence of an alkali, an additive, a ligand and a catalyst, a compound A and a compound B undergo a suzuk
- -
-
Paragraph 0082; 0083; 0084
(2017/07/31)
-
- Denitrogenative hydrofluorination of aromatic aldehyde hydrazones using (difluoroiodo)toluene
-
An operationally simple conversion of aromatic aldehyde hydrazones to monofluoromethylated arenes is reported. The hypervalent iodine reagent TolIF2 serves as an oxidant, converting the hydrazone to the corresponding diazo compounds. The by-product of the oxidation process, HF, is consumed in situ by a denitrogenative hydrofluorination reaction of the diazo group.
- Kulkarni, Kaivalya G.,Miokovic, Boris,Sauder, Matthew,Murphy, Graham K.
-
p. 9907 - 9911
(2016/10/31)
-
- Facile Access to Fluoromethylated Arenes by Nickel-Catalyzed Cross-Coupling between Arylboronic Acids and Fluoromethyl Bromide
-
The nickel-catalyzed fluoromethylation of arylboronic acids was achieved with the industrial raw material fluoromethyl bromide (CH2FBr) as the coupling partner. The reaction proceeded under mild reaction conditions with high efficiency; it features the use of a low-cost nickel catalyst, synthetic simplicity, and excellent functional-group compatibility, and provides facile access to fluoromethylated biologically relevant molecules. Preliminary mechanistic studies showed that a single-electron-transfer (SET) pathway is involved in the catalytic cycle.
- An, Lun,Xiao, Yu-Lan,Min, Qiao-Qiao,Zhang, Xingang
-
supporting information
p. 9079 - 9083
(2015/08/03)
-
- Palladium-Catalyzed Monofluoromethylation of Arylboronic Esters with Fluoromethyl Iodide
-
The first palladium-catalyzed direct monofluoromethylation of arylboronic esters to produce monofluoromethyl arenes is reported. The reaction is typically carried out at room temperature within 4 h and has a good functional group tolerance. The monofluoromethylating agent, CH2FI, was readily prepared via a halogen-exchange process.
- Hu, Jingyu,Gao, Bing,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
-
p. 3086 - 3089
(2015/06/30)
-
- Silver-catalyzed radical fluorination of alkylboronates in aqueous solution
-
We report herein an efficient and general method for the deboronofluorination of alkylboronates. Thus, with the catalysis of AgNO3, the reactions of various alkylboronic acids or their pinacol esters with Selectfluor reagent in acidic aqueous solution afforded the corresponding alkyl fluorides under mild conditions. A broad substrate scope and wide functional group compatibility were observed. A radical mechanism is proposed for this site-specific fluorination.
- Li, Zhaodong,Wang, Zhentao,Zhu, Lin,Tan, Xinqiang,Li, Chaozhong
-
supporting information
p. 16439 - 16443
(2015/01/09)
-
- Photocatalyzed benzylic fluorination: Shedding "light" on the involvement of electron transfer
-
The photocatalyzed oxidation of benzylic compounds by 1,2,4,5-tetracyanobenzene (TCB) in the presence of Selectfluor provides a synthetically efficient route to electron deficient, less substituted, and otherwise inaccessible benzylic fluorides. The virtue of this system is multifold: it is metal-free and mild, and the reagents are inexpensive. Mechanistically, the data suggest the intimate formation of intermediate radical cations in the key radical forming step, as opposed to a concerted hydrogen atom transfer process.
- Bloom, Steven,McCann, Michael,Lectka, Thomas
-
supporting information
p. 6338 - 6341
(2015/01/16)
-
- Efficient SN2 fluorination of primary and secondary alkyl bromides by copper(I) fluoride complexes
-
Copper(I) fluoride complexes ligated by phenanthroline derivatives have been synthesized and structurally characterized by X-ray crystallography. These complexes adopt as either ionic or neutral forms in the solid state, depending on the steric bulkiness of the substituent groups on the phenanthroline ligands. These complexes react with primary and secondary alkyl bromides to produce the corresponding alkyl fluorides in modest to good yields. This new method is compatible with a variety of important functional groups such as ether, thioether, amide, nitrile, methoxyl, hydroxyl, ketone, ester, and heterocycle moieties.
- Liu, Yanpin,Chen, Chaohuang,Li, Huaifeng,Huang, Kuo-Wei,Tan, Jianwei,Weng, Zhiqiang
-
p. 6587 - 6592
(2013/12/04)
-
- Dynamics of bond breaking in ion radicals. Mechanisms and reactivity in the reductive cleavage of carbon-fluorine bonds of fluoromethylarenes
-
The reductive cleavage mechanism and reactivity of the carbon-fluorine bonds in fluoromethylarenes are investigated, in liquid ammonia and in DMF, by means of cyclic voltammetry and/or redox catalysis as a function of the number of fluorine atoms and of the structure of the aryl moiety. The reduction of the trifluoro compounds, eventually leading to complete defluorination, involves the di- and monofluoro derivatives as intermediates. Carbenes do not transpire along the reaction pathway. Application of the intramolecular dissociative electron transfer model allows the quantitative rationalization, in terms of driving force and intrinsic barrier, of the variation of the cleavage reactivity of the primary anion radical with the number of fluorine atoms and of the structure of the aryl moiety as well as with the solvating properties of the medium. When, related to the structural factors thus uncovered, the primary anion radical generates the di- and monofluoro intermediates far from the electrode surface, their reduction occurs homogeneously giving rise to an apparently direct six-electron process according to an internal redox catalysis mechanism. Conversely, with rapid cleavages, the reduction of the di- and monofluoro intermediates takes place at the electrode surface and the stepwise expulsion of the fluorides ions transpire in the cyclic voltammetric patterns.
- Andrieux, Claude P.,Combellas, Catherine,Kanoufi, Fredéric,Savéant, Jean-Michel,Thiébault, André
-
p. 9527 - 9540
(2007/10/03)
-
- Selective electrolytic fluorinations in 70% HF/30% pyridine
-
The selective fluorination of compounds containing benzylic hydrogen atoms was accomplished by electrolysis in a mixture of 70% HF and 30% pyridine (Olah's reagent) using a square wave alternating current (1.76-2.75 V, 0.02-0.05 Hz) and Pt electrodes. This method can be used in the laboratory to prepare conveniently gram-size quantities of monofluorinated products. An ion radical mechanism has been proposed.
- Lee, Sarah M.,Roseman, Jamie M.,Zartman, C. Blair,Morrison, Eamonn P.,Harrison, Sean J.,Stankiewicz, Corrie A.,Middleton
-
-
- MECHANISMS OF FREE-RADICAL REACTIONS. XX. REACTIVITY IN THE FREE-RADICAL HALOGENATION REACTIONS OF ARYLFLUOROALKANES
-
The free-radical chlorination and bromination of meta- and para-substituted benzyl fluorides and 1,1-difluoro-2-phenylethane and also the chlorination of 1-fluoro-2-arylethanes by phenylchloroiodonium chloride and the bromination of meta- and para-substituted benzyl bromides were studied by the method of competing reactions.In all cases a good correlation is observed between log krel and the Brown ?+ constants.In cases where change in the reactivity in the transition from one reaction series to another is due mainly to the polar effect of the substituent whilethe selectivity is measured in relation to the polar effect direct relationships are observed between the reactivity and the selectivity.
- Dneprovskii, A. S.,Eliseenkov, E. V.
-
p. 711 - 719
(2007/10/02)
-