- δ-thiolactones as prodrugs of thiol-based glutamate carboxypeptidase II (GCPII) inhibitors
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δ-Thiolactones derived from thiol-based glutamate carboxypeptidase II (GCPII) inhibitors were evaluated as prodrugs. In rat liver microsomes, 2-(3-mercaptopropyl)pentanedioic acid (2-MPPA, 1) was gradually produced from 3-(2-oxotetrahydrothiopyran-3-yl)propionic acid (5), a thiolactone derived from 1. Compound 1 was detected in plasma at concentrations well above its IC 50 for GCPII following oral administration of 5 in rats. Consistent with the oral plasma pharmacokinetics, thiolactone 5 exhibited efficacy in a rat model of neuropathic pain following oral administration.
- Ferraris, Dana V.,Majer, Pavel,Ni, Chiyou,Slusher, C. Ethan,Rais, Rana,Wu, Ying,Wozniak, Krystyna M.,Alt, Jesse,Rojas, Camilo,Slusher, Barbara S.,Tsukamoto, Takashi
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Read Online
- Chemoselective Cleavage of Si-C(sp3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate)
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Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
- Matsuoka, Keitaro,Komami, Narumi,Kojima, Masahiro,Mita, Tsuyoshi,Suzuki, Kimichi,Maeda, Satoshi,Yoshino, Tatsuhiko,Matsunaga, Shigeki
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supporting information
p. 103 - 108
(2021/01/13)
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- Chemoselective Oxidation of p-Methoxybenzyl Ethers by an Electronically Tuned Nitroxyl Radical Catalyst
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The oxidation of p-methoxy benzyl (PMB) ethers was achieved using nitroxyl radical catalyst 1, which contains electron-withdrawing ester groups adjacent to the nitroxyl group. The oxidative deprotection of the PMB moieties on the hydroxy groups was observed upon treatment of 1 with 1 equiv of the co-oxidant phenyl iodonium bis(trifluoroacetate) (PIFA). The corresponding carbonyl compounds were obtained by treating the PMB-protected alcohols with 1 and an excess of PIFA.
- Hamada, Shohei,Sugimoto, Koichi,Elboray, Elghareeb E.,Kawabata, Takeo,Furuta, Takumi
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supporting information
p. 5486 - 5490
(2020/07/24)
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- Formyloxyacetoxyphenylmethane and 1,1-diacylals as versatile O-formylating and O-acylating reagents for alcohols
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Formyloxyacetoxyphenylmethane, symmetric 1,1-diacylals and mixed 1-pivaloxy-1-acyloxy-1-phenylmethanes have been used as moisture stable O-formylating and O-acylating reagents for primary and secondary alcohols, allylic alcohols and phenols under solvent/catalyst free conditions to afford their corresponding esters in good yield.
- Chapman, Robert S.L.,Francis, Molly,Lawrence, Ruth,Tibbetts, Joshua D.,Bull, Steven D.
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p. 6442 - 6452
(2018/10/02)
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- Synthesis of trifluoromethyl moieties by late-stage copper (I) mediated nucleophilic fluorination
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The nucleophilic fluorination of bromodifluoromethyl derivatives mediated by the complex (PPh3)3CuF is described. Under the reaction conditions, different trifluoroacetates, trifluoroketones, trifluoroarenes and trifluoroacetamides were obtained in good yields.
- Bermejo Góme, Antonio,González, Miguel A. Cortés,Lübcke, Marvin,Johansson, Magnus J.,Schou, Magnus,Szabó, Kálmán J.
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- Efficient photolytic C-H bond functionalization of alkylbenzene with hypervalent iodine(iii) reagent
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A practical approach to radical C-H bond functionalization by the photolysis of a hypervalent iodine(iii) reagent is presented. The photolysis of [bis(trifluoroacetoxy)iodo]benzene (PIFA) leads to the generation of trifluoroacetoxy radicals, which allows the smooth transformation of various alkylbenzenes to the corresponding benzyl ester compounds under mild reaction conditions.
- Sakamoto, Ryu,Inada, Tsubasa,Selvakumar, Sermadurai,Moteki, Shin A.,Maruoka, Keiji
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supporting information
p. 3758 - 3761
(2016/03/25)
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- Efficient DBU accelerated synthesis of 18F-labelled trifluoroacetamides
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Nucleophilic 18F-fluorination of bromodifluoromethyl derivatives was performed using [18F]Bu4NF in the presence of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). This novel procedure provided a diverse set of [18F]trifluoroacetamides in good to excellent radiochemical conversions. A mechanism where DBU acts as organomediator in this transformation is proposed.
- Gómez, Antonio Bermejo,Cortés González, Miguel A.,Lübcke, Marvin,Johansson, Magnus J.,Halldin, Christer,Szabó, Kálmán J.,Schou, Magnus
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supporting information
p. 13963 - 13966
(2016/12/09)
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- ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions
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A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhydride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with substrates having other functional groups and it is suitable for practical organic synthesis.
- Farhadi, Saeed,Jahanara, Kosar
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p. 368 - 375
(2014/04/03)
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- Unprecedented iron-catalyzed ester hydrogenation. Mild, selective, and efficient hydrogenation of trifluoroacetic esters to alcohols catalyzed by an iron pincer complex
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The synthetically important, environmentally benign hydrogenation of esters to alcohols has been accomplished in recent years only with precious-metal-based catalysts. Here we present the first iron-catalyzed hydrogenation of esters to the corresponding alcohols, proceeding selectively and efficiently in the presence of an iron pincer catalyst under remarkably mild conditions. The replacement of precious-metal catalysts by an iron complex was accomplished for the synthetically important, environmentally benign hydrogenation of esters to alcohols under mild conditions. The iron pincer complex (see scheme) selectively and efficiently catalyzes the hydrogenation of trifluoroacetates under remarkably mild conditions (5-25 bar and 40 °C).
- Zell, Thomas,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 4685 - 4689
(2014/05/20)
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- Palladium-catalyzed, asymmetric Mizoroki-Heck reaction of benzylic electrophiles using phosphoramidites as chiral ligands
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We report herein the first examples of asymmetric Mizoroki-Heck reactions using benzyl electrophiles. A new phosphoramidite was identified to be an effective chiral ligand in the palladium-catalyzed reaction. The reaction is compatible with polar functional groups and can be readily scaled up. Several cyclic olefins worked well as olefin components. Thirty-one examples are included.
- Yang, Zhigang,Zhou, Jianrong
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supporting information; experimental part
p. 11833 - 11835
(2012/09/08)
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- Flash chemistry extensively optimized: High-temperature Swern-Moffatt oxidation in an automated microreactor platform
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The generally accepted benefits of small lateral dimensions of microreactors (1 μm to 1 mm) enable a different way of performing synthetic chemistry: Extremely short contact times in the millisecond range can circumvent the need for performing highly exothermic and fast reactions at very low temperatures. In order to fully exploit this technology, such fast processes need to be redesigned and investigated for optimal reaction conditions, which can differ drastically from the ones traditionally applied. In a comprehensive study, we optimized the selective Swern-Moffatt oxidation of benzyl alcohol to benzaldehyde by varying five experimental parameters, including reaction time and temperature. Employing an ultrashort mixing and reaction time of only 32 ms, the optimal temperature was determined to be 70°C, approximately 150°C higher than in the conventional batch conditions. This remarkable difference shows both the potency of continuousflow chemistry as well as the urgency of a paradigm shift in reaction design for continuous-flow conditions.
- Nieuwland, Pieter J.,Koch, Kaspar,Van Harskamp, Noud,Wehrens, Ron,Van Hest, Jan C. M.,Rutjes, Floris P. J. T.
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experimental part
p. 799 - 805
(2010/07/07)
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- Design, synthesis and biological evaluation of novel fluorinated docetaxel analogues
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A series of novel fluorinated docetaxel analogues have been synthesized and evaluated in vitro and in vivo. Incorporated one, two or three fluorine atom(s) either at both meta position on C-2 benzolate and 3′-N-tert-butyloxyl group or only at 3′-N-tert-butyloxyl group has resulted in potent analogues which have comparable or superior in vitro and in vivo cytotoxicity to docetaxel. Among them, compounds 14d and 14e have displayed more potent cytotoxicity than docetaxel both in human cancer cell line SK-OV-3 in vitro and in human non-small cell lung cancer A549 xenografts in vivo. Preliminary data show that compound 14a has reduced acute animal toxicity in mice compared with docetaxel.
- Lu, Hong-Fu,Sun, Xun,Xu, Liang,Lou, Li-Guang,Lin, Guo-Qiang
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experimental part
p. 482 - 491
(2009/09/06)
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- Erbium(III) chloride: A very active acylation catalyst
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Erbium(iii) chloride is a powerful catalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidic anhydrides (Ac 2O, (EtCO)2O, (PriCO)2O, (Bu tCO)2O, and (CF3CO)2), without isomerization of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity. CSIRO 2007.
- Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Oliverio, Manuela,Procopio, Antonio,Russo, Beatrice,Tocci, Amedeo
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- PROCESS FOR PRODUCING ALDEHYDE COMPOUND OR KETONE COMPOUND WITH USE OF MICROREACTOR
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The method for producing an aldehyde or ketone compound from a corresponding primary or secondary alcohol at relatively high temperature within a short time with a high yield comprises a step (1) of reacting a sulfoxide compound with an activating agent to produce an activation reaction product; a step (2) of reacting the activation reaction product with a primary or secondary alcohol to produce an alkoxysulfonium salt; and a step (3) of reacting the reaction product with a base to produce an aldehyde or ketone; wherein at least one of the steps, preferably the step (1) and step (2), are carried out by using a microreactor.
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Page/Page column 24-25; 37-39
(2010/11/24)
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- Cobalt(II)-catalyzed direct acetylation of alcohols with acetic acid
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Cobalt(II) chloride hexahydrate (CoCl2·6H2O) efficiently catalyzes the acetylation of alcohols with AcOH in high yields. This protocol is also effective with other carboxylic acids, trifluoroacetic acid, propanoic acid, phenylacetic acid and benzoic acid, affording the corresponding acylated products in moderate to good yields. Removal of water is not necessary in these reactions. The catalyst can be filtered and recycled without loss of activity.
- Velusamy, Subbarayan,Borpuzari, Sarbani,Punniyamurthy
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p. 2011 - 2015
(2007/10/03)
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- Room-temperature Swern oxidations by using a microscale flow system
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(Equation Presented) Residence time controlled reaction: The Swern oxidation of alcohols has been accomplished by using a microscale flow system, consisting of micromixers and microscale tube reactors (see schematic representation ; DMSO = dimethylsulfoxide, TFAA = trifluoroacetic anhydride), at higher temperatures (-20 to 20°C) than those for conventional macroscale batch systems (-50°C or below).
- Kawaguchi, Tatsuya,Miyata, Hiroyuki,Ataka, Kikuo,Mae, Kazuhiro,Yoshida, Jun-Ichi
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p. 2413 - 2416
(2007/10/03)
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- Erbium(III) triflate as an extremely active acylation catalyst
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Erbium(III) triflate is a powerful catalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidic anhydrides {Ac 2O, (EtCO)2O, [(CH3)3CO] 2O, Bz2O, and (CF3CO)2O} without isomerisation of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity.
- Procopio, Antonio,Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Russo, Beatrice,Sindona, Giovanni
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p. 1465 - 1470
(2007/10/03)
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- Heterolytic decarboxylation involving acyltrifluoroacetyl peroxide intermediates
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Selective carboxylic acid decarboxylation was elaborated. Generation of acyltrifluoroacetyl peroxides from carboxylic peracids and trifluoroacetyl anhydride (Method A), as well as from trifluoroperacetic acid and acyltrifluoroacetyl anhydride (Method B), leads to simultaneous peroxide decomposition into the corresponding alkyltrifluoroacetates. DFT computations, as well as experimental data, support an acid-catalyzed heterolytic mechanism for acyltrifluoroacetyl peroxide decomposition.
- Krasutsky, Pavel A.,Kolomitsyn, Igor V.,Botov, Evgenij M.,Carlson, Robert M.,Semenova, Irina G.,Fokin, Andrey A.
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p. 8687 - 8691
(2007/10/03)
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- Tetraalkylfluoroformamidinium trifluoroacetate and preparation process of same
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The invention has disclosed a trifluoroacetoxylation agent and a preparation process of the agent, which is safe and ease to handle, very useful in industry, and represented by the formula (1); wherein R1to R4are a substituted or uns
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- Synthesis and reactivity of benzylic sulfonium salts: Benzylation of phenol and thiophenol under near-neutral conditions
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A series of benzyldimethylsulfonium - and related hydrogensulfate salts have been synthesized from the ternary system ArCH2OH:H2SO4: Me2S or tetrahydrothiophene. The salts are generally stable crystalline solids, but anomalously high reactivity is observed for 9-(anthrylmethyl)dimethylsulfonium hydrogensulfate. Selected sulfonium salts have been used for the O- and S-benzylation of phenol and thiophenol, respectively, in a two phase system under near-neutral conditions. The benzylation of oximes and benzimidazole under basic conditions is also described.
- Forrester,Jones,Newton,Preston
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p. 2871 - 2884
(2007/10/03)
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- A one-pot rapid synthesis of dithiocarbamates from alcohols using a polymer supported diethyl dithiocarbamate anion
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A polymer supported diethyl dithiocarbamate anion reacts with primary and secondary alcohols via their tirfluoracetates giving alkylated diethyl dithiocarbamates in good yields.
- Bandgar,Sadavarte,Uppalla
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p. 450 - 451
(2007/10/03)
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- Catalytic esterification of alcohols, carboxylic acids and transesterification reactions with cerium(IV) triflate
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Esterification reactions of alcohols with acetic, chloroacetic, trifluoroacetic, propionic, stearic, and benzoic acids were catalyzed with Ce(OTf)4 in a solvent or under solvent-free conditions with high yields. The formylation and acetylation of primary and secondary alcohols were also easily achieved in ethyl formate and ethyl acetate. A high retention of the configuration was observed in the acetylation and formylation of (-)-menthol.
- Iranpoor, Nasser,Shekarriz, Marzieh
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p. 455 - 458
(2007/10/03)
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- Carboxylic acids supported on silica: A smooth acylating agent for alcohols
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An alternative procedure for the esterification of alcohols by short-chain carboxylic acids supported on silica is presented.
- Da Graca Nascimento, Maria,Zanotto, Sandra Patricia,Scremin, Marivania,Rezende, Marcos Caroli
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p. 2715 - 2721
(2007/10/03)
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- Oxidation of C2, C3 and Higher Alkanes by a Ruthenium-Oxo System
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Barium ruthenate, BaRuO3(OH)2, when dissolved in TFA-CH2Cl2 containing a few equivalents of 2,2'-bipyridine, generates a highly reactive ruthenium-oxo system that is capable of oxidizing ethane and propane at room temeprature with good yields.
- Lau, Tai-Chu,Mak, Chi-Keung
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p. 943 - 944
(2007/10/02)
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- Phosphoric-Carboxylic Anhydrides. New Synthetic Procedures and Reactions with Nucleophiles. Reexamination of the Reaction of Se-alkyl-phosphoroselenoates with Alcohols and Mercuric Trifluoroacetate
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Phosphorus trimethylsilyl esters RR'P(O)OSiMe3 react smoothly with carboxylic anhydrides to give phosphoric-carboxylic anhydrides RR'P(O)-O-COR" in excellent yield.A similar reaction proceeds between stannyl esters RR'P(O)OSnMe3 and carboxylic anhydrides.We also have found that the anhydrides RR'P(O)-O-COCF3 are formed in almost quantitative yield when the phosphorus acid halides RR'P(O)X (X=Cl,Br,I) are allowed to react with trifluoroacetic anhydride in the presence of N-methylimidazole. We were able to confirm again that acyclic phosphoric-carboxylic anhydrides exhibit acetylating properties towards amines and alcohols.Our findings contradict with those of Wozniak, Krzyzanowska and Stec relating to the reaction of Se-alkylphosphoroselenoates RR'P(O)SeR" with mercuric trifluoroacetate Hg(OCOCF3)2.Our interpretation of this reaction differs entirely from those presented by the above mentioned authors. Key words: phosphorus-carboxylic anhydrides, Se-alkyl-phosphoroselenoates
- Wasiak, J.,Helinski, J.,Dabkowski, W.,Skrzypczynski, Z.,Michalski, J.
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p. 1027 - 1032
(2007/10/02)
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- TRIETHYL PHOSPHITE IN ORGANIC SYNTHESIS. A FACILE, ONE-POT CONVERSION OF ALCOHOLS INTO AMINES
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General protocols for converting primary, secondary, and tertiary alcohols into the corresponding primary amines are presented.
- Zwierzak, Andrzej
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- The Chemistry of Pyrrolic Compounds. LXII The Oxidative Cyclization of Bilenes-b: Identification of the Expelled Carbon Fragment
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Oxidative cyclization of the 1,19-dibenzylbilene-b salt (12) with copper(II) acetate in acetic acid /methanol yielded the expected meso-phenyporphyrin (13).Careful examination of the by-products by g.l.c./m.s. revealed the presence of benzyl acetate, indicating the fragmet excluded was lost at the alcohol oxidation level.When trifluoroacetic acid was present in the cyclization mixture benzyl trifluoroacetate was the only fragment identified. heating the meso-phenylprophyrin (13) yielded the cyclic ketonic prophyrin derivative (14).
- Atkinson, Errol J.,Brophy, Joseph J.,Clezy, Peter S.
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p. 383 - 391
(2007/10/02)
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- 2-(Trifluoroacetyloxy)pyridine as a Mild Trifluoroacetylating Reagent of Amines and Alcohols
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A new trifluoroacetylating reagent, 2-(trifluoroacetyloxy)pyridine (TFAP), was prepared by the reaction of 2-pyridinol and trifluoroacetic anhydride.TFAP has been found to be effective in the trifluoroacetylation of aliphatic and aromatic amines and alcohols including phenol under mild conditions.The reaction of p-nitrophenol with TFAP in ether gave the hydrogen-bonded complex between the phenol and 2-pyridone.This reagent has also been shown to be useful for the intramolecular dehydration of aldehyde oximes and amides to give nitriles in high yields.
- Keumi, Takashi,Shimada, Masakazu,Morita, Toshio,Kitajima, Hidehiko
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p. 2252 - 2256
(2007/10/02)
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- Anodic Oxidation of (Trimethylsilyl)methanes with ?-Electron Substituents in the Presence of Nucleophiles
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It was found that oxidation potentials of methanes with ?-electron substituents were decreased by introduction of a trimethylsilyl group.The anodic oxidation of benzyl-, allyl-, aryl(or alkyl)thiomethyl-, and aryloxymethyl-substituted trimethylsilanes smoothly proceeded in the presence of nucleophiles, e.g. alcohols and carboxylic acids, to eliminate the trimethylsilyl groups giving the corresponding alkoxylated and carboxylated products in moderate or high yields without full optimization of electrolytic conditions, while aminomethylsilanes did not undergo such a kind of anodic oxidation.
- Koizumi, Toshio,Fuchigami, Toshio,Nonaka, Tsutomu
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p. 219 - 225
(2007/10/02)
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- HYDROCARBON OXIDATIONS WITH CHROMYL TRIFLUOROACETATE
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Chromyl trifluoroacetate oxidizes hydrocarbons, including polyolefin polymers, to give predominately alcohols and ketones.The reaction is extremely rapid.A solution of n-hexane, for example, is oxidized upon mixing at -50 deg C.
- Suggs, J. William,Ytuarte, Larry
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p. 437 - 440
(2007/10/02)
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- OXIDATION BY THE SALTS OF METALS. IV. OXIDATIVE HALOGENATION OF TOLUENE AND PARA-SUBSTITUTED TOLUENES WITH ELECTRON-WITHDRAWING GROUPS PROMOTED BY CERIUM(IV) SALTS IN AQEOUS SOLUTIONS OF TRIFLUOROACETIC ACID
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The oxidation of toluene and para-substituted toluenes with electron-withdrawing groups (para-toluic acid, methyl para-toluate, and para-nitrotoluene) by ammonium cerium(IV) nitrate and ammonium cerium(IV) sulfate was investigated in aqueous solutions of trifluoroacetic acid in the presence of alkali-metal chlorides and bromides.The rate and selectivity of oxidative halogenation in the side chain and/or aromatic ring under the investigated conditions depends strongly both on the nature of the substrate and the halide ion and on the reaction conditions and the ligand environment of the cerium(IV) atom.The oxidation of nitrotoluene takes place only in the presence of the bromide-containing systems and leads to the production of 4-nitrobenzyl bromide.For the other substrates halogenation in the aromatic ring can be realized with yields close to quantitative with ammonium cerium(IV) nitrate as oxidizing agent in concentrated aqueous solutions of trifluoroacetic acid (10 vol.percent of water).It was shown that the halogenating agents in this case are mainly the products from oxidation of the halide ions by the nitronium ions formed in the strongly acidic medium from the nitrate ions contained in the ammonium cerium(IV) nitrate.Bromination of the substituted toluenes in the presence of ammonium cerium(IV) sulfate and in the ammonium cerium(IV) nitrate-alkali-metal bromide systems with more than 10 vol.percent of water takes mainly in the side chain and can be used as a method for the production of 4-substituted benzyl halides with preparative yields.The effect of the composition of the solvent and the ratio of the oxidizing agent and alkali-metal halide on the rate and selectivity of oxidative bromination was studied.Possible reaction mechanisms are discussed.
- Makhon'kov, D.I.,Cheprakov, A.V.,Rodkin, M.A.,Mil'chenko, A.Yu.,Beletskaya, I.P.
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- OXIDATION BY THE SALTS OF METALS. VI. OXIDATIVE IODINATION OF AROMATIC SUBSTRATES, PROMOTED BY Co(III), Mn(III), AND Ce(IV) COMPOUNDS IN AQUEOUS TRIFLUOROACETIC ACID
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The direct iodination of benzene, halogenobenzenes, and p-methoxycarbonyltoluene in trifluoroacetic acid and its aqueous solutions with iodine or alkali-metal iodides was studied in the presence of Co(III) and Mn(III) acetates and ammonium cerium(IV) sulfate, which make it possible to obtain the respective iodoarenes with high yields under mild conditions.In the case of toluene the reaction is complicated by the formation of α-oxidation products.It is assumed that the iodinating agent is trifluoroacetyl hypoiodite, formed as a result of the oxidation of the iodine by the salt of the metal having variable valence.The highest yields of the iodoarenes were obtained with 90percent aqueous trifluoroacetic acid.
- Makhon'kov, D. I.,Cheprakov, A. V.,Rodkin, M. A.,Beletskaya, I. P.
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p. 1003 - 1006
(2007/10/02)
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- OXIDATION BY THE SALTS OF METALS. III. OXIDATIVE HALOGENATION OF TOLUENE BY ALKALI-METAL CHLORIDES AND BROMIDES, PROMOTED BY THE SALTS OF TRIVALENT COBALT AND MANGANESE IN TRIFLUOROACETIC ACID AND ITS AQUEOUS SOLUTIONS
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The oxidation of toluene by the stoichiometric amounts of cobalt(III) and manganese(III) acetates (C6H5CH3:M(3+) = 0.5) in the presence of alkali-metal chlorides and bromides (M(3+):Hlg(-) = 1-2) in trifluoroacetic acid and its aqueous solutions (5-50 vol
- Makhon'kov, D. I.,Rodkin, M. A.,Beletskaya, I. P.
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p. 1445 - 1452
(2007/10/02)
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- Oxidative Displacement of Halogen from Alkyl Halides by Phenyliodine(III) Dicarboxylates
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The reaction of alkyl iodides with aryliodine(III) dicarboxylates affords as the main product the ester derived through substitution of iodine by an acyloxy group; in some cases α-iodoalkyl esters are also formed along with other minor products.Certain reactive bromides and chlorides react along similar lines.The mechanism of these reactions is briefly discussed.
- Gallos, John,Varvoglis, Anastasios
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p. 1999 - 2002
(2007/10/02)
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- REACTION OF THIOLSULFINATES WITH TRIHALOACETIC ANHYDRIDES. II. ADDITION OF SULFENYL TRIHALOACETATES TO OLEFINS
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Treatment of thiolsulfinates with trifluoro- or trichloroacetic anhydride at -20 deg C in the presence of various olefins in carbon tetrachloride afforded the corresponding β-trifluoro- or trichloroacetoxy sulfides in good yields.The β-trihaloacetoxy sulfides are considered to be resulted by the electrophilic addition of the sulfenyl trihaloacetates, formed as transient intermediates, to olefins.The addition takes place stereospecifically in trans manner and the regioselectivity for the addition with unsymmetrical olefins obeyed the Markownikoff orientation rule, except 3,3-dimethyl-1-butene which gave initially the anti-Markownikoff product 3 due to the steric hindrance, however the adduct 3 is readily converted to the Markownikoff product 22 upon heating.Since the addition is highly regioselective and stereospecific, this is a very convenient procedure for the syntheses of β-trihaloacetoxy sulfides.
- Morishita, Tsuyoshi,Furukawa, Naomichi,Oae, Shigeru
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p. 2539 - 2546
(2007/10/02)
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- REACTION OF THIOLSULFINATES WITH TRIHALOACETIC ANHYDRIDES-I EVIDENCE FOR THE FORMATION OF SULFENYL AND SULFINYL CARBOXYLATES
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Thiosulfinates react with trifluoro- or trichloroacetic anhydride to give equimolar mixtures of the coresponding disulfides and sulfinyl trifluoro- or trichloroacetates which are in equilibria with sulfenyl carboxylates.Although the equilibrium lies far toward sulfinyl carboxylates at room temperature, addition of olefins to the mixed solution of sulfinyl carboxylate and corresponding disulfide affords the adducts which are formed in the reaction between the corresponding sulfenyl carboxylates and the olefins.Meanwhile, treatment of carboxylic acid silver salts with sulfinyl chlorides also gives sulfinyl carboxylates, howevver, sulfinyl carboxylates have not been successfully isolated yet.
- Morishita, Tsuyoshy,Furukawa, Naomichi,Oae, Shigeru
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p. 3115 - 3120
(2007/10/02)
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- The Preparation of 2,4,6-Triphenylpyrylium Trifluoromethanesulphonate, Fluorosulphonate, Ethoxysulphonate, Naphthalene-2-sulphonate, Stannochloride, Trichloroacetate, and Trifluoroacetate and other Pyrylium Trifluoromethanesulphonates and their Reactions
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The title pyrylium salts are all readily prepared in high yield from 1,3,5-triphenylpent-2-ene-1,5-dione.Amines react with the trifluoromethanesulphonate, naphthalene-2-sulphonate, and trifluoroacetate to give the corresponding pyridinium salts in high yi
- Katritzky, Alan R.,El-Mowafy, Azzahra M.,Marzorati, Liliana,Patel, Ranjan C.,Thind, Sukhpal S.
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p. 4001 - 4030
(2007/10/02)
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