- A novel synthesis of trifluoromethyl ethers via xanthates, utilizing BrF3
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Alcohols were transformed into trifluoromethyl ethers by converting them to xanthates in almost quantitative yields followed by a reaction with bromine trifluoride, a reagent rarely used in organic chemistry.
- Ben-David, Iris,Rechavi, Dalit,Mishani, Eyal,Rozen, Shlomo
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- Direct Trifluoromethylation of Alcohols Using a Hypervalent Iodosulfoximine Reagent
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The direct trifluoromethylation of a variety of aliphatic alcohols using a hypervalent iodosulfoximine reagent afforded the corresponding ethers in moderate to good yields (14–72 %). Primary, secondary, and even tertiary alcohols, including examples derived from natural products, underwent this transformation in the presence of catalytic amounts of zinc bis(triflimide). Typical reaction conditions involved a neat mixture of 6.0 equivalents of the alcohol with 1.0 equivalent of the reagent, with the majority of reactions complete within 2 h with 2.5 mol % of the Lewis acid catalyst. Furthermore, experimental evidence was provided that the C?O bond-forming process occurred via the coordination of the alcohol to the iodine atom and subsequent reductive elimination.
- Kalim, Jorna,Duhail, Thibaut,Pietrasiak, Ewa,Anselmi, Elsa,Magnier, Emmanuel,Togni, Antonio
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supporting information
p. 2638 - 2642
(2021/01/21)
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- Radical C?H Trifluoromethoxylation of (Hetero)arenes with Bis(trifluoromethyl)peroxide
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Trifluoromethoxylated (hetero)arenes are of great interest for several disciplines, especially in agro- and medicinal chemistry. Radical C?H trifluoromethoxylation of (hetero)arenes represents an attractive approach to prepare such compounds, but the high cost and low atom economy of existing .OCF3 radical sources make them unsuitable for the large-scale synthesis of trifluoromethoxylated building blocks. Herein, we introduce bis(trifluoromethyl)peroxide (BTMP, CF3OOCF3) as a practical and efficient trifluoromethoxylating reagent that is easily accessible from inexpensive bulk chemicals. Using either visible light photoredox or TEMPO catalysis, trifluoromethoxylated arenes could be prepared in good yields under mild conditions directly from unactivated aromatics. Moreover, TEMPO catalysis allowed for the one-step synthesis of valuable pyridine derivatives, which have been previously prepared via multi-step approaches.
- Dix, Stefan,Golz, Paul,Schmid, Jonas R.,Riedel, Sebastian,Hopkinson, Matthew N.
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supporting information
p. 11554 - 11558
(2021/07/09)
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- Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow
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The first example of photocatalytic trifluoromethoxylation of arenes and heteroarenes under continuous-flow conditions is described. Application of continuous-flow microreactor technology allowed to reduce the residence time up to 16 times in comparison t
- Cendón, Borja,Gulías, Moisés,Ho, Michelle,No?l, Timothy,Nyuchev, Alexander V.,Sambiagio, Carlo,Struijs, Job J. C.,Wan, Ting,Wang, Ying
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supporting information
p. 1305 - 1312
(2020/07/10)
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- DIFLUOROMETHOXYLATION AND TRIFLUOROMETHOXYLATION COMPOSITIONS AND METHODS FOR SYNTHESIZING SAME
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The present invention provides a compound having the structure (I), a processing of making the compound; and a process of using the compound as a reagent for the difluoromethoxylation and trifluoromethoxylation of arenes or heteroarenes.
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Page/Page column 43; 46; 56; 57-58
(2019/09/18)
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- Visible-Light Photoredox-Catalyzed and Copper-Promoted Trifluoromethoxylation of Arenediazonium Tetrafluoroborates
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We report the development of photoredox-catalyzed and copper-promoted trifluoromethoxylation of arenediazonium tetrafluoroborates, with trifluoromethyl arylsulfonate (TFMS) as the trifluoromethoxylation reagent. This new method takes advantage of visible-light photoredox catalysis to generate the aryl radical under mild conditions, combined with copper-promoted selective trifluoromethoxylation. The reaction is scalable, tolerates a wide range of functional groups, and proceeds regioselectively under mild reaction conditions. Furthermore, mechanistic studies suggested that a Cs[Cu(OCF3)2] intermediate might be generated during the reaction.
- Yang, Shaoqiang,Chen, Miao,Tang, Pingping
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supporting information
p. 7840 - 7844
(2019/05/15)
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- Radical Trifluoromethoxylation of Arenes Triggered by a Visible-Light-Mediated N?O Bond Redox Fragmentation
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A simple trifluoromethoxylation method enables non-directed functionalization of C?H bonds on a range of substrates, providing access to aryl trifluoromethyl ethers. This light-driven process is distinctly different from conventional procedures and occurs through an OCF3 radical mechanism mediated by a photoredox catalyst, which triggers an N?O bond fragmentation. The pyridinium-based trifluoromethoxylation reagent is bench-stable and provides access to synthetic diversity in lead compounds in an operationally simple manner.
- Jelier, Benson J.,Tripet, Pascal F.,Pietrasiak, Ewa,Franzoni, Ivan,Jeschke, Gunnar,Togni, Antonio
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supporting information
p. 13784 - 13789
(2018/09/14)
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- Redox-Active Reagents for Photocatalytic Generation of the OCF3 Radical and (Hetero)Aryl C?H Trifluoromethoxylation
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The trifluoromethoxy (OCF3) radical is of great importance in organic chemistry. Yet, the catalytic and selective generation of this radical at room temperature and pressure remains a longstanding challenge. Herein, the design and development of a redox-active cationic reagent (1) that enables the formation of the OCF3 radical in a controllable, selective, and catalytic fashion under visible-light photocatalytic conditions is reported. More importantly, the reagent allows catalytic, intermolecular C?H trifluoromethoxylation of a broad array of (hetero)arenes and biorelevant compounds. Experimental and computational studies suggest single electron transfer (SET) from excited photoredox catalysts to 1 resulting in exclusive liberation of the OCF3 radical. Addition of this radical to (hetero)arenes gives trifluoromethoxylated cyclohexadienyl radicals that are oxidized and deprotonated to afford the products of trifluoromethoxylation.
- Zheng, Weijia,Lee, Johnny W.,Morales-Rivera, Cristian A.,Liu, Peng,Ngai, Ming-Yu
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supporting information
p. 13795 - 13799
(2018/09/27)
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- Catalytic C?H Trifluoromethoxylation of Arenes and Heteroarenes
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The intermolecular C?H trifluoromethoxylation of arenes remains a long-standing and unsolved problem in organic synthesis. Herein, we report the first catalytic protocol employing a novel trifluoromethoxylating reagent and redox-active catalysts for the direct (hetero)aryl C?H trifluoromethoxylation. Our approach is operationally simple, proceeds at room temperature, uses easy-to-handle reagents, requires only 0.03 mol % of redox-active catalysts, does not need specialized reaction apparatus, and tolerates a wide variety of functional groups and complex structures such as sugars and natural product derivatives. Importantly, both ground-state and photoexcited redox-active catalysts are effective. Detailed computational and experimental studies suggest a unique reaction pathway where photoexcitation of the trifluoromethoxylating reagent releases the OCF3 radical that is trapped by (hetero)arenes. The resulting cyclohexadienyl radicals are oxidized by redox-active catalysts and deprotonated to form the desired products of trifluoromethoxylation.
- Zheng, Weijia,Morales-Rivera, Cristian A.,Lee, Johnny W.,Liu, Peng,Ngai, Ming-Yu
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supporting information
p. 9645 - 9649
(2018/03/21)
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- Trifluoromethyl Benzoate: A Versatile Trifluoromethoxylation Reagent
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Trifluoromethyl benzoate (TFBz) is developed as a new shelf-stable trifluoromethoxylation reagent, which can be easily prepared from inexpensive starting materials using KF as the only fluorine source. The synthetic potency of TFBz is demonstrated by trifluoromethoxylation-halogenation of arynes, nucleophilic substitution of alkyl (pseudo)halides, cross-coupling with aryl stannanes, and asymmetric difunctionalization of alkenes. The unprecedented trifluoromethoxylation-halogenation of arynes proceeds smoothly at room temperature with the aid of a crown ether-complexed potassium cation, which significantly stabilizes the trifluoromethoxide anion derived from TFBz.
- Zhou, Min,Ni, Chuanfa,Zeng, Yuwen,Hu, Jinbo
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supporting information
p. 6801 - 6805
(2018/05/31)
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- Fluorodecarboxylation: Synthesis of aryl trifluoromethyl ethers (ArOCF3) and thioethers (ArSCF3)
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Fluorodecarboxylation of aryloxydifluoroacetic acid (ArOCF2CO2H) and arylmercaptodifluoroacetic acid (ArSCF2CO2H) towards ArXCF3 (X = O, S) using silver (I) salts in the presence of Selectfluor in a biphasic system with trifluoroacetic acid additive is discussed.
- Krishanmoorthy, Sankarganesh,Schnell, Simon D.,Dang, Huong,Fu, Fang,Prakash, G.K. Surya
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p. 130 - 135
(2017/09/06)
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- O-Trifluoromethylation of Phenols: Access to Aryl Trifluoromethyl Ethers by O-Carboxydifluoromethylation and Decarboxylative Fluorination
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A new strategy for the synthesis of aryl trifluoromethyl ethers (ArOCF3) by combining O-carboxydifluoromethylation of phenols and subsequent decarboxylative fluorination is reported. This protocol allows easy construction of functionalized trifluoromethoxybenzenes and trifluoromethylthiolated arenes (ArSCF3) in moderate to good yields. Moreover, it utilizes accessible and inexpensive reagents sodium bromodifluoroacetate and SelectFluor II and, thus, is practical for O-trifluoromethylation of phenols. The potential application of this method is demonstrated with the preparation of a plant-growth regulator, Flurprimidol.
- Zhou, Min,Ni, Chuanfa,He, Zhengbiao,Hu, Jinbo
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supporting information
p. 3754 - 3757
(2016/08/16)
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- Xenon Difluoride Mediated Fluorodecarboxylations for the Syntheses of Di- and Trifluoromethoxyarenes
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XeF2 is demonstrated to be a more proficient fluorine-transfer reagent than either NFSI or Selectfluor in fluorodecarboxylations of both mono- and difluoroaryloxy acetic acid derivatives. This method efficiently converts a wide range of neutral and electron-poor substrates to afford the desired di- and trifluoromethyl aryl ethers in good to excellent yields. The purifications are facile, and the reaction times are less than 5 min, which makes these fluorodecarboxylations promising for future PET-imaging applications.
- Chatalova-Sazepin, Claire,Binayeva, Meruyert,Epifanov, Maxim,Zhang, Wei,Foth, Paul,Amador, Carolyn,Jagdeo, Manu,Boswell, Benjamin R.,Sammis, Glenn M.
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p. 4570 - 4573
(2016/09/28)
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- Fluorodecarboxylation for the Synthesis of Trifluoromethyl Aryl Ethers
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The synthesis of mono-, di-, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6-difluoropyridine increased the reactivity of AgF2, thereby increasing the range of functional groups and electronic properties of the aryl groups that are tolerated. The reaction conditions used for the formation of trifluoromethyl aryl ethers also served to form difluoromethyl and monofluoromethyl aryl ethers.
- Zhang, Qing-Wei,Brusoe, Andrew T.,Mascitti, Vincent,Hesp, Kevin D.,Blakemore, David C.,Kohrt, Jeffrey T.,Hartwig, John F.
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supporting information
p. 9758 - 9762
(2016/08/10)
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- Direct trifluoro-methoxylation of aromatics with perfluoro-methyl- hypofluorite
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The reactivity of CF3OF (FTM) has been widely studied especially in halogenated olefinic systems and its use in pharmaceutical synthesis as a mild radical and electrophilic fluorinating agent is well documented. On the other hand, the chemical behavior of the perfluoro-methyl-hypofluorite with aromatic substrates is much less studied. Up to now few and scattered data regarding its use as electrophilic fluorinating agent of variously substituted aromatic compounds are found in the literature. In this work the reactivity of CF3OF with simple electron rich and electron poor aromatics (α,α,α-trifluoro-toluene, toluene, benzene, chloro-benzene, methoxybenzene) has been investigated. The possibility of selectively bind the trifluoro-methoxy group (via radical mechanism) or the fluorine atom (via electrophilic addition) by varying the reaction conditions has been explored. In particular we have observed that the trifluoro-methoxy free radical substitution can be the main synthetic pathway if the reaction is promoted by an independent and steady source of CF3O radical.
- Venturini, Francesco,Navarrini, Walter,Famulari, Antonino,Sansotera, Maurizio,Dardani, Patrizia,Tortelli, Vito
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experimental part
p. 43 - 48
(2012/08/14)
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- Lability of the trifluoromethyl group of trifluoromethoxybenzenes under HF/Lewis acid conditions
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The trifluoromethyl functionality of trifluoromethoxybenzenes (trifluoromethyl phenyl ethers) becomes labile under HF/Lewis acid conditions. Substrates with an unsubstituted para-position shed their -CF3 groups while performing a Friedel-Crafts reaction upon another substrate molecule's trifluoromethoxy group to generate p-rosolic acids. Substrates that had blocking groups at the para-positions reacted ortho. The electron donating substituents methoxy and phenoxy interfered with the formation of rosolic acids.
- Belter, Randolph K.
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scheme or table
p. 1302 - 1307
(2011/02/22)
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- Flash Thermolysis of Aryl Trifluoroacetates: A New Approach to Trifluoromethylated Aromatic Compounds
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Flash thermolysis of aryl trifluoroacetates yield trifluoromethyl aromatic compounds along with trifluoromethoxy compounds.
- Kobayashi, Y.,Nakazato, A.,Kumadaki, I.,Filler, R.
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p. 467 - 470
(2007/10/02)
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- Herbicidal sulfonamides
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This invention pertains to benzenesulfonamides and their use as agricultural chemicals.
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- Preparation of aryl trifluoromethyl ethers
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A one-step process for the synthesis of aryl trifluoromethyl ethers by reacting phenol or certain substituted phenols with a perhalomethane and hydrogen fluoride is provided. The compounds produced by the process of this invention are useful intermediates in the production of dyestuffs and pharmaceuticals.
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