- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
-
In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
- Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
-
supporting information
p. 15396 - 15405
(2021/10/12)
-
- Fluorination of arylboronic esters enabled by bismuth redox catalysis
-
Bismuth catalysis has traditionally relied on the Lewis acidic properties of the element in a fixed oxidation state. In this paper, we report a series of bismuth complexes that can undergo oxidative addition, reductive elimination, and transmetallation in a manner akin to transition metals. Rational ligand optimization featuring a sulfoximine moiety produced an active catalyst for the fluorination of aryl boronic esters through a bismuth (III)/bismuth (V) redox cycle. Crystallographic characterization of the different bismuth species involved, together with a mechanistic investigation of the carbonfluorine bond-forming event, identified the crucial features that were combined to implement the full catalytic cycle.
- Planas, Oriol,Wang, Feng,Leutzsch, Markus,Cornella, Josep
-
p. 313 - 317
(2020/01/28)
-
- Oxidatively Induced Aryl-CF3 Coupling at Diphosphine Nickel Complexes
-
This communication describes the synthesis of a series of diphosphine NiII(Ph)(CF3) complexes and studies of their reactivity toward oxidatively induced Ph-CF3 bond-forming reductive elimination. Treatment of these complexes with the one-electron outer-sphere oxidant ferrocenium hexafluorophosphate (FcPF6) affords benzotrifluoride, but the yield varies dramatically as a function of diphosphine ligand. Diphosphines with bite angles of less than 92° afforded 3. In contrast, those with bite angles between 95 and 102° formed PhCF3 in yields ranging from 62 to 77%.
- Bour, James R.,Roy, Pronay,Canty, Allan J.,Kampf, Jeff W.,Sanford, Melanie S.
-
supporting information
p. 3 - 7
(2020/01/03)
-
- Mechanism of Photoredox-Initiated C-C and C-N Bond Formation by Arylation of IPrAu(I)-CF3 and IPrAu(I)-Succinimide
-
Herein, we report on the photoredox-initiated gold-mediated C(sp2)-CF3 and C(sp2)-N coupling reactions. By adopting gold as a platform for probing metallaphotoredox catalysis, we demonstrate that cationic gold(III) complexes are the key intermediates of the C-C and C-N coupling reactions. The high-valent gold(III) intermediates are accessed by virtue of photoredox catalysis through a radical chain process. In addition, the bond-forming step of the coupling reactions is the reductive elimination from cationic gold(III) intermediates, which is supported by isolation and crystallographic characterization of key Au(III) intermediates.
- Kim, Suhong,Toste, F. Dean
-
p. 4308 - 4315
(2019/01/25)
-
- The Difluoromethylated Organogold(III) Complex cis-[Au(PCy3)(4-F-C6H4)(CF2H)(Cl)]: Preparation, Characterization, and Its C(sp2)-CF2H Reductive Elimination
-
The preparation of the difluoromethylated organogold(III) complex cis-[Au(PCy3)(4-F-C6H4)(CF2H)(Cl)] (3) and its Ar-CF2H reductive elimination are described. In the presence of 1.0 equiv of AgSbF6 or AgPF6, compound 3 underwent a quantitative Ar-CF2H reductive elimination in less than 1.0 min at 25 °C, while the lack of silver salt resulted in Ar-CF2H reductive elimination from complex 3 in 1,1,2,2-tetrachloroethane (CCl2HCCl2H) after 80 min at 115 °C to afford the elimination product p-F-PhCF2H (4) and (Cy3P)Au(Cl) in quantitative yields. On the basis of the mechanistic studies of the kinetics of the reaction and DFT calculation, a concerted Ar-CF2H bond-forming pathway for the Ar-CF2H reductive elimination from organogold(III) complex 3 is proposed.
- Liu, Shuanshuan,Kang, Kai,Liu, Shihan,Wang, Decai,Wei, Ping,Lan, Yu,Shen, Qilong
-
p. 3901 - 3908
(2018/10/25)
-
- Nucleophilic deoxyfluorination of phenols via aryl fluorosulfonate intermediates
-
This report describes a method for the deoxyfluorination of phenols with sulfuryl fluoride (SO2F2) and tetramethylammonium fluoride (NMe4F) via aryl fluorosulfonate (ArOFs) intermediates. We first demonstrate that the reaction of ArOFs with NMe4F proceeds under mild conditions (often at room temperature) to afford a broad range of electronically diverse and functional group-rich aryl fluoride products. This transformation was then translated to a one-pot conversion of phenols to aryl fluorides using the combination of SO2F2 and NMe4F. Ab initio calculations suggest that carbon-fluorine bond formation proceeds via a concerted transition state rather than a discrete Meisenheimer intermediate.
- Schimler, Sydonie D.,Cismesia, Megan A.,Hanley, Patrick S.,Froese, Robert D.J.,Jansma, Matthew J.,Bland, Douglas C.,Sanford, Melanie S.
-
supporting information
p. 1452 - 1455
(2017/02/10)
-
- METHOD FOR AROMATIC FLUORINATION
-
Disclosed is a fluorination method comprising providing an aryl fluorosuifonate and a fluorinating reagent to a reaction mixture; and reacting the aryl fluorosuifonate and the fluorinating reagent to provide a fluorinated aryl species. Also disclosed is a fluorination method comprising providing, a salt comprising a cation and an aryloxyiate, and SO2F2 to a reaction mixture; reacting the SO2F2 and the ammonium salt to provide a fluorinated aryl species. Further disclosed a fluorination method comprising providing a compound having the structure Ar-OH to a reaction mixture; where A is an aryl or heteroaryl; providing SO2F2 to the reaction mixture; providing a fluorinating reagent to the reaction mixture; reacting the SO2F2, the fluorinating reagent and the compound having the structure Ar-OH to provide a fluorinated aryl species having the structure Ar-F.
- -
-
Paragraph 0047-0049
(2017/12/18)
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- Method for synthesizing trifluoromethyl aromatic compounds
-
The invention aims to provide a method for converting arylamine into trifluoromethyl aromatic compounds under simple conditions. The trifluoromethyl aromatic compounds can be widely applied to the fields of pesticides, medicines, organic materials and the like. The method is characterized by comprising steps of (1), synthesizing Toni reagents alpha from sodium periodate, 2-iodobenzoic acid, acetic anhydride, cesium fluoride and Ruppert reagents; (2), dissolving the arylamine and hydrochloric acid in 1, 2-dichloroethane, stirring the arylamine, the hydrochloric acid and the 1, 2-dichloroethane for 5-10 min to obtain mixtures, adding tert-butyl nitrite into the mixtures under low-temperature conditions, carrying out stirring reaction for 30-60 min to obtain reaction products, adding tetrafluoroboric acid tetra-acetonitrile copper, the Toni reagents alpha and sodium bicarbonate into the reaction products and carrying micro-heat reaction for 10-20 hours; sequentially filtering, washing and drying reaction liquid after reaction is completely carried out and carrying out column chromatography separation and purification on the reaction liquid to obtain target products. The method has the advantage that the trifluoromethyl aromatic compounds can be widely applied to the fields of pesticides, medicines, organic materials and the like.
- -
-
Paragraph 0037; 0038
(2017/08/29)
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- Stoichiometric and Catalytic Aryl-Perfluoroalkyl Coupling at Tri-tert-butylphosphine Palladium(II) Complexes
-
This Communication describes studies of Ph-RF (RF = CF3 or CF2CF3) coupling at Pd complexes of general structure (PtBu3)PdII(Ph)(RF). The CF3 analogue participates in fast Ph-CF3 coupling (II complex. Furthermore, they show that this undesired pathway can be circumvented by changing from a CF3 to a CF2CF3 ligand. Ultimately, the insights gained from stoichiometric studies enabled the identification of Pd(PtBu3)2 as a catalyst for the Pd-catalyzed cross-coupling of aryl bromides with TMSCF2CF3 to afford pentafluoroethylated arenes.
- Ferguson, Devin M.,Bour, James R.,Canty, Allan J.,Kampf, Jeff W.,Sanford, Melanie S.
-
supporting information
p. 11662 - 11665
(2017/09/07)
-
- Reactions of aromatic compounds with xenon difluoride
-
Reactions of substituted benzenes C6H5R (R = Me, F, Cl, Br, CF3, NO2) with xenon difluoride in the presence of boron trifluoride–diethyl ether complex in weakly acidic (1,1,1,3,3-pentafluorobutane) and weakly basic media (acetonitrile) have been studied. These reactions lead to the formation of fluorobenzene derivatives FC6H4R (isomer mixture) together with isomeric difluorobenzenes and fluorinated and non-fluorinated biphenyls. The results have been compared with previously reported data obtained in other solvents using other catalysts.
- Bardin,Adonin, N. Yu.
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p. 1400 - 1407
(2016/11/29)
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- Trifluoromethylation of (hetero)aryl iodides and bromides with copper(i) chlorodifluoroacetate complexes
-
A new copper-mediated trifluoromethylation reaction using copper(i) chlorodifluoroacetate complexes as reagents is reported. The complex [L2Cu][O2CCF2Cl] (L = bpy, dmbpy, phen) reacted with (hetero)aryl iodides and bromides in the presence of CsF in DMF at 75 °C to afford the trifluoromethylarenes in good to excellent yields. High compatibility with various chemical functions or (hetero)cycles was also observed in the reaction. A reaction mechanism involving a difluorocarbene intermediate, along with a subsequent formation of a -CF3 anion was proposed.
- Lin, Xiaoxi,Li, Zhengyu,Han, Xiaoyan,Weng, Zhiqiang
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p. 75465 - 75469
(2016/08/24)
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- Isolation and characterization of copper(III) trifluoromethyl complexes and reactivity studies of aerobic trifluoromethylation of arylboronic acids
-
The isolation, characterization and reactivity of transition metal trifluoromethyl complexes are fundamental and challenging topics in trifluoromethylation chemistry. We report herein the synthesis and isolation of two new complexes [(phen)CuI(PPh3)2]+[CuIII(CF3)4]- (2) and (phen)CuIII(CF3)3 (3) as well as a known complex (bpy)CuIII(CF3)3 (4) at room temperature. 2 and 3 have been fully characterized using 1H, 19F, 31P NMR, elemental analyses and X-ray crystallography. Reactivity studies indicate that 2 is unreactive toward arylboronic acids. In contrast, 3 and 4 can react with various aryl and heteroaryl boronic acids to deliver trifluoromethylated arenes in good to quantitative yields under mild conditions. The presence of a fluoride additive in DMF under aerobic conditions is crucial to these reactions. This study provides fundamental information about the structure and reactivity of elusive Cu(iii) trifluoromethyl complexes that have been proposed as relevant reactive intermediates in many trifluoromethylation reactions.
- Zhang, Song-Lin,Bie, Wen-Feng
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p. 70902 - 70906
(2016/08/05)
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- Copper-catalysed synthesis of trifluoromethyl(hetero)arenes from di(hetero)aryl-λ3-iodanes
-
An efficient synthesis of trifluoromethylated (hetero)arenes has been achieved through the regioselective copper-catalyzed trifluoromethylation of di(hetero)aryl-λ3-iodanes, employing readily available trifluoromethyltrimethylsilane. The reaction works well for both symmetrical and unsymmetrical di(hetero)aryl-λ3-iodanes with good regioselectivity and also tolerates diverse functional groups such as bromo, iodo, cyano, nitro, ester, ketone and enolizable ketone.
- Pandey, Vinay Kumar,Anbarasan, Pazhamalai
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p. 18525 - 18529
(2016/02/27)
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- Ruthenium-catalyzed nucleophilic fluorination of halobenzenes
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The first π-coordination-catalyzed nucleophilic fluorination of unactivated aryl halides has been demonstrated. Chlorobenzene reacts with alkali metal fluorides (CsF, KF) in the presence of a Cp?Ru catalyst at 120-180°C to give fluorobenzene.
- Konovalov, Andrey I.,Gorbacheva, Evgeniya O.,Miloserdov, Fedor M.,Grushin, Vladimir V.
-
supporting information
p. 13527 - 13530
(2015/09/01)
-
- Photoinitiated oxidative addition of CF3I to gold(I) and facile aryl-CF3 reductive elimination
-
Herein we report the mechanism of oxidative addition of CF3I to Au(I), and remarkably fast Caryl-CF3 bond reductive elimination from Au(III) cations. CF3I undergoes a fast, formal oxidative addition to R3PAuR' (R = Cy, R' = 3,5-F2-C 6H4, 4-F-C6H4, C6H 5, 4-Me-C6H4, 4-MeO-C6H4, Me; R = Ph, R' = 4-F-C6H4, 4-Me-C6H 4). When R' = aryl, complexes of the type R3PAu(aryl) (CF3)I can be isolated and characterized. Mechanistic studies suggest that near-ultraviolet light (λmax = 313 nm) photoinitiates a radical chain reaction by exciting CF3I. Complexes supported by PPh3 undergo reversible phosphine dissociation at 110 °C to generate a three-coordinate intermediate that undergoes slow reductive elimination. These processes are quantitative and heavily favor C aryl-I reductive elimination over Caryl-CF3 reductive elimination. Silver-mediated halide abstraction from all complexes of the type R3PAu(aryl)(CF3)I results in quantitative formation of Ar-CF3 in less than 1 min at temperatures as low as -10 °C.
- Winston, Matthew S.,Wolf, William J.,Toste, F. Dean
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p. 7777 - 7782
(2014/06/10)
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- Conversion of aromatic amino into trifluoromethyl groups through a Sandmeyer-type transformation
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A novel strategy for aromatic trifluoromethylation by converting amino into trifluoromethyl groups via a Sandmeyer-type reaction is reported. The transformation involves diazotization of the aromatic amines with tert-butyl nitrite and hydrochloric acid to form aryldiazonium chlorides, followed by trifluoromethylation with trifluoromethylsilver at low temperature. Various readily available aromatic amines are smoothly converted under mild conditions. Georg Thieme Verlag Stuttgart. New York.
- Wang, Xi,Xu, Yan,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 2143 - 2148
(2014/08/18)
-
- Silver-mediated fluorination of potassium aryltrifluoroborates with Selectfluor Dedicated to Professor Andrea Vasella on the occasion of his 71st birthday
-
A simple and practical procedure for the silver-mediated fluorination of aryl- and heteroaryltrifluoroborates with electrophilic fluorine from Selectfluor and LiOH·H2O is presented. The reaction procedure is simple and easy to set up, the process produces fluorinated arenes and heteroarenes in good to excellent yields and a wide range of electronically and structurally diverse substrates are tolerated.
- Dubbaka, Srinivas Reddy,Narreddula, Venkateswara Reddy,Gadde, Satyanarayana,Mathew, Thresen
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p. 9676 - 9681
(2015/01/08)
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- FLUORINATION OF ARYL COMPOUNDS
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The invention provides compositions and methods of using the compositions in fluorinating aryl precursors containing a leaving group replaceable by a fluorine atom. The compositions include a metal ion source, a electrophilic fluorine source, a base, and a compound, which is an aryl precursor of the aryl fluoride, and which has a leaving group replaceable by the fluorine atom. Exemplary methods of the invention make use of such compositions and methods to prepare an aryl fluoride compound. In an exemplary embodiment, the electrophilic fluorine source is a source of 18F.
- -
-
Paragraph 00117
(2014/07/22)
-
- Copper-mediated fluorination of arylboronate esters. Identification of a Copper(III) fluoride complex
-
A method for the direct conversion of arylboronate esters to aryl fluorides under mild conditions with readily available reagents is reported. Tandem reactions have also been developed for the fluorination of arenes and aryl bromides through arylboronate ester intermediates. Mechanistic studies suggest that this fluorination reaction occurs through facile oxidation of Cu(I) to Cu(III), followed by rate-limiting transmetalation of a bound arylboronate to Cu(III). Fast C-F reductive elimination is proposed to occur from an aryl-copper(III)-fluoride complex. Cu(III) intermediates have been generated independently and identified by NMR spectroscopy and ESI-MS.
- Fier, Patrick S.,Luo, Jingwei,Hartwig, John F.
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p. 2552 - 2559
(2013/03/29)
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- Direct synthesis of a trifluoromethyl copper reagent from trifluoromethyl ketones: Application to trifluoromethylation
-
Being economic with fluorine: The direct synthesis of CuCF3 from a cuprate reagent and trifluoromethyl ketones, as one of the most economical and efficient trifluoromethyl sources, was accomplished. The advantages of this method are all of reagents employed are low-cost, operation is simple, and the yield of CuCF3 is virtually quantitative (see scheme). Furthermore, three types of trifluoromethylations smoothly proceeded to provide the corresponding products in high yields. Copyright
- Serizawa, Hiroki,Aikawa, Kohsuke,Mikami, Koichi
-
supporting information
p. 17692 - 17697
(2014/01/17)
-
- Trifluoromethylation of aryl and heteroaryl halides with fluoroform-derived CuCF3: Scope, limitations, and mechanistic features
-
Fluoroform-derived CuCF3 recently discovered in our group exhibits remarkably high reactivity toward aryl and heteroaryl halides, performing best in the absence of extra ligands. A broad variety of iodoarenes undergo smooth trifluoromethylation with the ligandless CuCF3 at 23-50 C to give the corresponding benzotrifluorides in nearly quantitative yield. A number of much less reactive aromatic bromides also have been trifluoromethylated, including pyridine, pyrimidine, pyrazine, and thiazole derivatives as well as aryl bromides bearing electron-withdrawing groups and/or ortho substituents. Only the most electrophilic chloroarenes can be trifluoromethylated, e.g., 2-chloronicotinic acid. Exceptionally high chemoselectivity of the reactions (no side-formation of arenes, biaryls, and C2F5 derivatives) has allowed for the isolation of a large number of trifluoromethylated products in high yield on a gram scale (up to 20 mmol). The CuCF3 reagent is destabilized by CuX coproduced in the reaction, the magnitude of the effect paralleling the Lewis acidity of CuX: CuCl > CuBr > CuI. While SNAr and SRN1 mechanisms are not operational, there is a well-pronounced ortho effect, i.e., the enhanced reactivity of ortho-substituted aryl halides 2-RC6H4X toward CuCF3. Intriguingly, this ortho-effect is observed for R = NO2, COOH, CHO, COOEt, COCH3, OCH3, and even CH3, but not for R = CN. The fluoroform-derived CuCF3 reagent and its reactions with haloarenes provide an unmatched combination of reactivity, selectivity, and low cost.
- Lishchynskyi, Anton,Novikov, Maxim A.,Martin, Eddy,Escudero-Adan, Eduardo C.,Novak, Petr,Grushin, Vladimir V.
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p. 11126 - 11146
(2013/12/04)
-
- Silver-mediated trifluoromethylation of aryldiazonium salts: Conversion of amino group into trifluoromethyl group
-
A novel strategy for aromatic trifluoromethylation by converting aromatic amino group into CF3 group is reported herein. This method, which can be considered as trifluoromethylation variation of the classic Sandmeyer reaction, uses readily available aromatic amines as starting materials and is performed under mild conditions.
- Wang, Xi,Xu, Yan,Mo, Fanyang,Ji, Guojing,Qiu, Di,Feng, Jiajie,Ye, Yuxuan,Zhang, Songnan,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 10330 - 10333
(2013/08/23)
-
- Mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates
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This communication describes a mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates with N-fluoro-2,4,6-trimethylpyridinium triflate. This protocol demonstrates broad substrate scope and functional group tolerance, and does not require the use of any noble metal additives. The reaction is proposed to proceed via an arylcopper(III) fluoride intermediate.
- Ye, Yingda,Sanford, Melanie S.
-
supporting information
p. 4648 - 4651
(2013/05/09)
-
- FLUORINATION OF ORGANIC COMPOUNDS
-
Methods for fluorinating organic compounds are described herein.
- -
-
Page/Page column 24
(2012/11/06)
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- Copper-catalysed process for the production of substituted or unsubstituted trifluormethylated aryl and heteroaryl compounds
-
The present invention relates to a process for the production of triffluoromethylated unsubstituted or substituted aryl or heteroaryl compounds which comprises reacting an unsubstituted or substituted aryl or heteroaryl halide with a trifluoroacetate of formula (I) or (II), wherein R1 is hydrogen or a C1-C5 alkyl group and M an alkali metal or an ammonium ion, in the presence of a copper salt as catalyst and an anorganic halogenide salt or a trifluoroacetacid salt as activator compound.
- -
-
Page/Page column 5; 8
(2012/05/20)
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- PROCESS TO OBTAIN A TRIFLUOROMETHYLATING COMPOSITION
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Process to obtain a trifluoromethylating composition which comprises the reaction between a copper (I) source and a base in the presence of a solvent and between the resulting cuprating reagent with fluoroform.
- -
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Page/Page column 56
(2012/09/11)
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- Practical method for the Cu-mediated trifluoromethylation of arylboronic acids with CF3 radicals derived from NaSO2CF3 and tert-butyl hydroperoxide (TBHP)
-
A mild and practical protocol for the copper-mediated trifluoromethylation of aryl and heteroaryl boronic acids using NaSO2CF3 (Langlois' reagent) and TBHP is described. The reaction proceeds at room temperature under ambient conditions, and the products can be readily purified by extraction or column chromatography.
- Ye, Yingda,Kuenzi, Stefan A.,Sanford, Melanie S.
-
supporting information
p. 4979 - 4981,3
(2012/12/12)
-
- Practical method for the Cu-mediated trifluoromethylation of arylboronic acids with CF3 radicals derived from NaSO2CF3 and tert-butyl hydroperoxide (TBHP)
-
A mild and practical protocol for the copper-mediated trifluoromethylation of aryl and heteroaryl boronic acids using NaSO2CF3 (Langlois' reagent) and TBHP is described. The reaction proceeds at room temperature under ambient conditions, and the products can be readily purified by extraction or column chromatography.
- Ye, Yingda,Künzi, Stefan A.,Sanford, Melanie S.
-
supporting information
p. 4979 - 4981
(2013/01/15)
-
- Copper-mediated fluorination of aryl iodides
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The synthesis of aryl fluorides has been studied intensively because of the importance of aryl fluorides in pharmaceuticals, agrochemicals, and materials. The stability, reactivity, and biological properties of aryl fluorides can be distinct from those of the corresponding arenes. Methods for the synthesis of aryl fluorides, however, are limited. We report the conversion of a diverse set of aryl iodides to the corresponding aryl fluorides. This reaction occurs with a cationic copper reagent and silver fluoride. Preliminary results suggest this reaction is enabled by a facile reductive elimination from a cationic arylcopper(III) fluoride.
- Fier, Patrick S.,Hartwig, John F.
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supporting information; experimental part
p. 10795 - 10798
(2012/08/07)
-
- Merging visible-light photocatalysis and transition-metal catalysis in the copper-catalyzed trifluoromethylation of boronic acids with CF3I
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This communication describes the development of a mild method for the cross-coupling of arylboronic acids with CF3I via the merger of photoredox and Cu catalysis. This method has been applied to the trifluoromethylation of electronically diverse aromatic and heteroaromatic substrates and tolerates many common functional groups.
- Ye, Yingda,Sanford, Melanie S.
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supporting information; experimental part
p. 9034 - 9037
(2012/07/13)
-
- A general strategy for the perfluoroalkylation of arenes and arylbromides by using arylboronate esters and [(phen)CuRF]
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A versatile method for the synthesis of aryl perfluoroalkanes from arenes and aryl bromides is described. Substituted arenes or aryl bromides are converted in situ to an aryl boronate ester that readily undergoes perfluoroalkylation in air with [(phen)CuRF]. A broad range of aryl bromide substrates were perfluoroalkylated in good yield for the first time. [(phen)CuCF3] is now commercially available and has been prepared on 20g scale. Copyright
- Litvinas, Nichole D.,Fier, Patrick S.,Hartwig, John F.
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supporting information; scheme or table
p. 536 - 539
(2012/02/16)
-
- Direct cupration of fluoroform
-
We have found the first reaction of direct cupration of fluoroform, the most attractive CF3 source for the introduction of the trifluoromethyl group into organic molecules. Treatment of CuX (X = Cl, Br, I) with 2 equiv of MOR (M = K, Na) in DMF or NMP produces novel alkoxycuprates that readily react with CF3H at room temperature and atmospheric pressure to give CuCF3 derivatives. The CuCl and t-BuOK (1:2) combination provides best results, furnishing the CuCF3 product within seconds in nearly quantitative yield. As demonstrated, neither CF3- nor CF2 mediate the Cu-CF3 bond formation, which accounts for its remarkably high selectivity. The fluoroform-derived CuCF3 solutions can be efficiently stabilized with TREAT HF to produce CuCF 3 reagents that readily trifluoromethylate organic and inorganic electrophiles in the absence of additional ligands such as phenanthroline. A series of novel Cu(I) complexes have been structurally characterized, including K(DMF)[Cu(OBu-t)2] (1), Na(DMF)2[Cu(OBu-t)2] (2), [K8Cu6(OBu-t)12(DMF)8(I)] + I- (3), and [Cu4(CF3) 2(C(OBu-t)2)2(μ3-OBu-t) 2] (7).
- Zanardi, Alessandro,Novikov, Maxim A.,Martin, Eddy,Benet-Buchholz, Jordi,Grushin, Vladimir V.
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experimental part
p. 20901 - 20913
(2012/03/07)
-
- Deoxyfluorination of phenols
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An operationally simple ipso fluorination of phenols with a new deoxyfluorination reagent is presented.
- Tang, Pingping,Wang, Weike,Ritter, Tobias
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supporting information; experimental part
p. 11482 - 11484
(2011/10/02)
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- Simple, stable, and easily accessible well-defined CuCF3 aromatic trifluoromethylating agents
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Give me an F: Exceptionally easy to make in over 90 yield (see scheme) and air-stable in the solid state, [(Ph3P)3Cu(CF3)] is a remarkable example of a rarely encountered well-defined Cu(I) trifluoromethylating agent and a convenient starting material for the synthesis of other CuCF3 complexes, such as [(phen)Cu(PPh3)(CF 3)]. Copyright
- Tomashenko, Olesya A.,Escudero-Adan, Eduardo C.,Martinez Belmonte, Marta,Grushin, Vladimir V.
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supporting information; experimental part
p. 7655 - 7659
(2011/10/02)
-
- Copper-mediated trifluoromethylation of arylboronic acids by trifluoromethyl sulfonium salts
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The ligand-free trifluoromethylation of arylboronic acids with a [Ph 2SCF3]+[OTf]-/Cu(0) system has been carefully investigated. Aryl-, alkenyl- and heteroarylboronic acids with a variety of functional groups were suitable substrates for this reaction. It is suggested that a CuCF3 species is formed under the reaction conditions.
- Zhang, Cheng-Pan,Cai, Ji,Zhou, Chang-Bing,Wang, Xiao-Ping,Zheng, Xing,Gu, Yu-Cheng,Xiao, Ji-Chang
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supporting information; experimental part
p. 9516 - 9518
(2011/10/02)
-
- Silver-mediated fluorination of aryl silanes
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A regiospecific silver-mediated fluorination of aryl silanes is reported. The reaction is operationally simple, and employs Ag2O as readily available, inexpensive silver source, which can be recovered.
- Tang, Pingping,Ritter, Tobias
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supporting information; experimental part
p. 4449 - 4454
(2011/08/03)
-
- Mechanistic and computational studies of oxidatively-induced Aryl-CF 3 bond-formation at Pd: Rational design of room temperature aryl trifluoromethylation
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This article describes the rational design of first generation systems for oxidatively induced Aryl-CF3 bond-forming reductive elimination from PdII. Treatment of (dtbpy)PdII(Aryl)(CF3) (dtbpy = di-tert-butylbipyridine) with NFTPT (N-fluoro-1,3,5-trimethylpyridinium triflate) afforded the isolable PdIV intermediate (dtbpy)Pd IV(Aryl)(CF3)(F)(OTf). Thermolysis of this complex at 80 °C resulted in Aryl-CF3 bond-formation. Detailed experimental and computational mechanistic studies have been conducted to gain insights into the key reductive elimination step. Reductive elimination from this PdIV species proceeds via pre-equilibrium dissociation of TfO- followed by Aryl-CF3 coupling. DFT calculations reveal that the transition state for Aryl-CF3 bond formation involves the CF3 acting as an electrophile with the Aryl ligand serving as a nucleophilic coupling partner. These mechanistic considerations along with DFT calculations have facilitated the design of a second generation system utilizing the tmeda (N,N,N′,N′-tetramethylethylenediamine) ligand in place of dtbpy. The tmeda complexes undergo oxidative trifluoromethylation at room temperature.
- Ball, Nicholas D.,Gary, J. Brannon,Ye, Yingda,Sanford, Melanie S.
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supporting information; experimental part
p. 7577 - 7584
(2011/06/25)
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- Copper-catalyzed trifluoromethylation of aryl iodides with potassium (trifluoromethyl)trimethoxyborate
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Potassium (trifluoromethyl)trimethoxyborate is introduced as a new source of CF3 nucleophiles in copper-catalyzed trifluoromethylation reactions. The crystalline salt is stable on storage, easy to handle, and can be obtained in near-quantitative yields simply by mixing B(OMe)3, CF3SiMe3, and KF. The trifluoromethylation reagent allows the conversion of various aryl iodides into the corresponding benzotrifluorides in high yields under mild, base-free conditions in the presence of catalytic quantities of a CuI/1,10-phenanthroline complex.
- Knauber, Thomas,Arikan, Fatih,Roeschenthaler, Gerd-Volker,Goossen, Lukas J.
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experimental part
p. 2689 - 2697
(2011/04/15)
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- Efficient synthesis of aryl fluorides
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Chemical Equation Presented Creating C-F bonds: A novel electrophilic fluorination of aryl and heteroaryl Crignard reagents has been discovered and was used for the efficient synthesis of various aryl fluoride derivatives (see picture; THF = tetrahydrofuran).
- Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
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experimental part
p. 2219 - 2222
(2010/06/17)
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- FLUORINATION OF ORGANIC COMPOUNDS
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Methods for fluorinating organic compounds are described herein.
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Page/Page column 91
(2010/07/10)
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- Fluorination of boronic acids mediated by silver(I) Triflate
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A regiospecific Ag-mediated fluorination reaction of aryl- and alkenylboronic acids and esters Is reported. The fluorination reaction uses commercially available reagents, does not require the addition of exogenous ligands, and can be performed on a multigram scale. This report discloses the first practical reaction sequence from arylboronic acid to aryl fluorides.
- Furuya, Takeru,Ritter, Toblas
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supporting information; experimental part
p. 2860 - 2863
(2009/12/05)
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- SYSTEM FOR FLUORINATING ORGANIC COMPOUNDS
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Described herein are fluorinated organic compounds and methods of making fluorinated organic compounds, for example, using palladium complexes. Also described herein are compositions and kits containing compounds and palladium complexes described herein.
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Page/Page column 171-173
(2009/10/09)
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- Palladium-mediated fluorination of arylboronic acids
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(Chemical Equation Presented) Saving the best for last: Novel palladium complexes allow mild, two-step fluorination of aryl boronic acids (see scheme). The reaction is regiospecific, functional-group tolerant, has a broad substrate scope, and is ideally suited for the introduction of fluorine substituents at a late stage for aryl fluoride synthesis.
- Furuya, Takeru,Kaiser, Hanns Martin,Ritter, Tobias
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supporting information; experimental part
p. 5993 - 5996
(2009/03/11)
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- Room-temperature nucleophilic aromatic fluorination: Experimental and theoretical studies
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(Chemical Equation Presented) Taming the reagent: The use of anhydrous tetrabutylammonium fluoride (TBAFanh) in nucleophilic aromatic substitution reactions, including variants of the selective halogen-exchange and fluorodenitration processes (see scheme), was investigated. It was shown that TBAFanh permits these reactions to be performed under surprisingly mild conditions if it is used in relatively nonpolar media.
- Sun, Haoran,DiMagno, Stephen G.
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p. 2720 - 2725
(2007/10/03)
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- Preparation process of fluorine substituted aromatic compound
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A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
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- Facile preparation of aromatic fluorides by deaminative fluorination of aminoarenes using hydrogen fluoride combined with bases
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One-pot deaminative fluorination of aminoarenes including heteroaromatics, namely, diazotization of aminoarenes followed by in situ fluoro-dediazoniation of the corresponding diazonium ions, was successfully accomplished to produce fluoroarenes in high yields by using hydrogen fluoride combined with base solutions. The diazotization stage has been found to play the most important part in yielding fluoroarenes effectively. It was greatly influenced by the composition of the HF solution and enhanced by employing appropriate amounts of bases such as pyridine under carefully controlled conditions. The fluoro-dediazoniation stage was effectively accelerated photochemically to afford fluoroarenes having polar substituents such as hydroxyl, nitro and so on in high yields.
- Yoneda,Fukuhara
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- Aryl fluoride syntheses involving reactions of aryllead triacetates with boron trifluoride-diethyl ether complex
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Aryllead(IV) triacetates react at room temperature with BF3.Et2O to give the corresponding aryl fluoride in moderate to good yields; triarylboroxines, electron rich aryltrimethylsilanes and some arenes, which yield aryllead triacetates in acid catalysed reactions with lead tetraacetate, are converted directly into aryl fluorides when stirred with lead tetraacetate in BF3.Et2O. An investigation of the mechanism of the fluoro-deplumbation reaction indicates that it probably proceeds by acid catalysed heterolytic cleavage of the C-Pb bond to produce an aryl cation.
- De Meio,Morgan,Pinhey
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p. 8129 - 8138
(2007/10/02)
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- Aryloxyheteroarylpropylamines, their preparation and use
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The present invention relates to aryloxyheteroarylpropylamines of formula I wherein, X is 2- or 3-thienyl-, furanyl or pyrrolyl, all of which are unsubstituted or optionally substituted; and, R is 3,4-methylenedioxyphenyl, aryl or heteroaryl, all of which are unsubstituted or optionally substituted; and, R1 and R2 are hydrocarbyl substituents, containing 1 to 11 carbon atoms, all of which are unsubstituted or optionally substituted; or hydrogen; or, R1 and R2 together form a 5, 6 or 7 membered ring containing at least one nitrogen atom, or optionally contains two nitrogen atoms, one or two oxygen atom(s) or one or two sulfur atom(s) or a combination thereof, which ring is unsubstituted or optionally substituted,a method of preparing the same and to pharmaceutical compositions comprising the compounds., The compounds of the invention have activity against calcium overload in brain cells, and are useful in the treatment of anoxia, traumatic injury, ischemia, migraine, epilepsy, Parkinson's disease, Alzheimer's disease and other neurodegenerative diseases.
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