- Direct bromodeboronation of arylboronic acids with CuBr2 in water
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An efficient and practical method has been developed for the preparation of aryl bromides via the direct bromodeboronation of arylboronic acids with CuBr2 in water. This strategy provides several advantages, such as being ligand-free, base-free, high yielding, and functional group tolerant.
- Tang, Yan-Ling,Xia, Xian-Song,Gao, Jin-Chun,Li, Min-Xin,Mao, Ze-Wei
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supporting information
(2021/01/05)
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- Reactivity of a frustrated Lewis pair and small-molecule activation by an isolable arduengo carbene-B{3,5-(CF3)2C6H 3}3 complex
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Tris[3,5-bis(trifluoromethyl)phenyl]borane reacts with the sterically demanding Arduengo carbenes 1,3-di-tert-butylimidazolin-2-ylidene and 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene to form isolable normal adducts. In the case of 1,3-di-tert-butylimidazolin-2-ylidene, the adduct exhibits dynamic behaviour in solution and frustrated-Lewis-pair (FLP) reactivity. Fast cleavage of dihydrogen and THF, the C-H activation of phenylacetylene, and carbon dioxide fixation were achieved by using solutions of this adduct in benzene. This adduct is stable at room temperature in the absence of suitable substrates; however, thermal rearrangement into an abnormal carbene-borane adduct can be observed. In contrast, the 1,3-bis(2,6- diisopropylphenyl)imidazolin-2-ylidene adduct exhibits no evidence of FLP reactivity or of dissociation in solution. DFT calculations confirmed the experimental behaviour and stability of these carbene-borane adducts. Frustrated but not frustrating: Arduengo carbene 1,3-di-tert-butylimidazolin-2-ylidene and tris[3,5-bis(trifluoromethyl)phenyl]borane form an isolable adduct (see scheme) that shows frustrated-Lewis-pair (FLP) reactivity towards H2, CO2, and other small molecules. Copyright
- Kolychev, Eugene L.,Bannenberg, Thomas,Freytag, Matthias,Daniliuc, Constantin G.,Jones, Peter G.,Tamm, Matthias
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supporting information
p. 16938 - 16946
(2013/03/28)
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- 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; experimental part
p. 536 - 539
(2012/02/16)
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- Meta halogenation of 1,3-disubstituted arenes via iridium-catalyzed arene borylation
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We report the meta halogenation of 1,3-disubstituted arenes to form 3,5-disubstituted aryl bromides and chlorides by using iridium-catalyzed arene borylation chemistry. Iridium-catalyzed borylation of arenes with B2pin2, followed by reaction of the boronic ester with copper(II) bromide or chloride converts arylboronic esters to the corresponding aryl halides. A variety of arenes containing alkoxy, alkyl, halogen, nitrile, ester, amide, and pivaloyl and TIPS-protected alcohols were converted to the corresponding 3,5-disubstituted aryl bromides and chlorides in yields ranging from 46% to 85%. In addition, 2,6-disubstituted and 3-substituted pyridines were converted to the 4-halo and 5-halopyridines, respectively. The utility of this methodology was demonstrated by the formal conversion of nicotine to Altinicline in three steps with an overall yield of 61% using meta bromination of nicotine as the first step. Copyright
- Murphy, Jaclyn M.,Liao, Xuebin,Hartwig, John F.
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p. 15434 - 15435
(2008/09/19)
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- 1,3-Bis(trifluoromethyl)benzene derivatives
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A method of manufacture of 3,5-bis(trifluoromethyl)bromobenzene, comprising the addition of a brominating reagent to a mixture of 3,5-bis(trifluoromethyl)benzene together with at least one of sulphuric acid or oleum in the absence of acetic acid. A method of production of 3,5-bis(trifluoromethyl)acetophenone comprising the reaction of 3,5-bis(trifluoromethyl)phenyl magnesium bromide with acetyl chloride in the presence of cuprous chloride. A method of production of 3,5-bis(trifluoromethyl)acetophenone comprising the steps of reacting 3,5-bis(trifluoromethyl)phenyl magnesium bromide with acetic anhydride, adding water, and recovering the product by azeotropic distillation. A method of removal of impurities including 3,5-bis(trifluoromethyl)acetate, 4-bromobutyl acetate and 4-chlorobutyl acetate from a preparation of 3,5-bis(trifluoromethyl)acetophenone, the method comprising heating the 3,5-bis(trifluoromethyl)acetophenone with a dilute solution of alkali. A method of production of 3,5-bis(trifluoromethyl)phenyl magnesium bromide comprising the reaction of 3,5-bis(trifluoromethyl)bromobenzene with magnesium in a solvent whilst maintaining the temperature of the reactants above 20° C. and below the reflux temperature of the solvent.
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- An improved preparation of 3,5-bis(trifluoromethyl)acetophenone and safety considerations in the preparation of 3,5-bis(trifluoromethyl)phenyl Grignard reagent
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An improved and efficient bromination of 3,5-bis(trifluoromethyl)benzene was developed. A safe and reliable preparation of the potentially explosive 3,5-bis(trifluoromethyl)phenyl Grignard and 3-trifluoromethylphenyl Grignard reagents, from the precursor bromides, is described. Reaction System Screening Tool (RSST) and Differential Thermal Analysis (DTA) studies suggest these trifluoromethylphenyl Grignard reagents can detonate on loss of solvent contact or upon moderate heating. When prepared and handled according to the methods described herein, these Grignard reagents can be safely prepared and carried on to advanced intermediates.
- Leazer Jr., Johnnie L.,Cvetovich, Raymond,Tsay, Fuh-Rong,Dolling, Ulf,Vickery, Thomas,Bachert, Donald
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p. 3695 - 3698
(2007/10/03)
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- Process for the synthesis of 1-(3,5-bis(trifluoromethyl)-phenyl)ethan-1-one
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The present invention is concerned with a novel process for the preparation of 1-(3,5-bis(trifluromethyl)phenyl)ethan-1-one (CAS 30071-93-3). This compound is useful as an intermediate in the synthesis of therapeutic agents.
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- A convenient new method for the bromination of deactivated aromatic compounds
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Treatment of deactivated aromatic compounds with N-bromosuccinimide in trifluoroacetic acid solvent in the presence of sulfuric acid gave the corresponding monobromoaromatic compounds in good to excellent yields.
- Duan, Jianxin,Zhang, Lian Hao,Dolbier Jr., William R.
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p. 1245 - 1246
(2007/10/03)
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- A simple and efficient method of preparing α-bromo carboxylic acids
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A new and convenient method for α-bromination of aliphatic carboxylic acids is reported. Heating carboxylic acids for 16 hours at 85 °C in trifluoroacetic acid with 1.5 equivalents of N-bromosuccinimide and a catalytic amount of concentrated H2SO4 leads to good yields of the respective α-bromocarboxylic acids.
- Zhang, Lian Hao,Duan, Jianxin,Xu, Yuelian,Dolbier Jr., William R.
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p. 9621 - 9622
(2007/10/03)
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- 1-bromo-3,5-bis(trifhioromethyl)benzene: A versatile starting material for organometallic synthesis
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1-Bromo-3,5-bis(trifluoromethyl)benzene (1) can be selectively prepared by treatment of 1,3-bis(fluorornethyl)benzene with N,N′-dibromo-5,5-dimethylhydantoin in strongly acidic media. A number of synthetically useful reactions via 3,5bis{trifluoromethyl)phenylmagnesium, -lithium, and -copper intermediates were accomplished. VCH Verlagsgesellschaft mbH, , 1996.
- Porwisiak, Jacek,Schlosser, Manfred
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p. 233 - 235
(2007/10/02)
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- REACTIONS OF ORGANIC COMPOUNDS WITH SF4-HF-HALOGENATING AGENT SYSTEMS VI. REACTIONS OF BENZENE AND ITS DERIVATIVES WITH SF4-HF-Cl2(Br2)
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In the reactions of benzene-carboxylic and -dicarboxylic acids with SF4-HF-Cl2(Br2), apart from the conversion of carboxyls into trifluoromethyl groups, there occurs the halogenation of the benzene ring with the formation of the corresponding chloro- and bromo-containing (trifluoromethyl)- and bis(trifluoromethyl)-benzenes.
- Kunshenko, B. V.,Omarov, V. O.,Muratov, N. N.,Mikhailevskii, S. M.,Yagupol'skii, L. M.
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p. 108 - 112
(2007/10/02)
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- Preparation of Fluorine-Containing Phenylacetylenes by the Method of Introduction of the Ethynyl Group Using 1,1-Dichloro-2,2-difluroethene
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Phenylacetylenes (ArCCH) having fluoro- or trifluoromethyl substituents (o-, m-, p-F; o-, m-, p-CF3; 2,4-, 2,5-, 2,6-, 3,5-(CF3)2) have been prepared from bromobenzenes (ArBr) and benzenes (ArH) using 1,1,-dichloro-2,2-difluoroethene (1) by a two-step route: ArLi or ArMgBr->ArCF=CCl2->ArCCLi.Upon careful treatment at -70 deg C with 1, o-fluorophenyllithium gave o-FC6H4CF=CCl2 in good yield, together with benzyne-derived products, such as o-(o-FC6H4)C6H4CF=CCl2.Lithiation of m-bis(trifluoromethyl)benzene at 0 deg C for 9 h (24 h) followed by treatment with bromine gave 1-bromo-2,4-, 2,6-, and 3,5-bis(trifluoromethyl)benzene in 35 (38), 31 (36), and 8percent (6percent) yield, respectively.
- Kodaira, Kazuo,Okuhara, Kunio
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p. 1625 - 1632
(2007/10/02)
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- 4-ARYL-3-(DIMETHYLAMINOMETHYL)THIACYCLOHEXAN-4-OLS INCLUDING THE THIA ANALOGUE OF TRAMADOL; SYNTHESIS AND ANALGETIC ACTIVITY
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Mannich reaction of thiacyclohexan-4-one with dimethylamine and paraformaldehyde afforded 3-(dimethylaminomethyl)thiacyclohexan-4-one (XIV) which was subjected to reactions with a series of arylmagnesium bromides.The products were mixtures of trans- and cis-amino alcohols III-XII from which the predominating trans-components were mostly obtained by crystallization of hydrochlorides or chromatography of bases.The tramadol (I) analogue, i.e. the 3-methoxy compound V, was prepared in the form of both racemates and their relative configuration was confirmed by the IR spectra.Compound V was demethylated to the 3-hydroxyphenyl analogue XIII, transformed to the bis-onium salt XVI, partially N-demethylated to the N-monodemethyl analogue XVII, and oxidized to the sulfoxide XX and to the sulfone N-oxide XXI.Some of the amino alcohols (III-V, VIII, IX, XIII) showed clear analgetic activity in the writhing syndrome inhibition test in mice; the 3-methoxy and 3-hydroxy compounds (V and XIII) were the most active ones, the latter being slightly more active than tramadol (I).
- Urban, Jiri,Svatek, Emil,Ryska, Miroslav,Metys, Jan,Wildt, Stanislav,Protiva, Miroslav
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p. 1340 - 1351
(2007/10/02)
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