Methyl Trichloroacetate Research Articles

Synthesis of dimethyl carbonate from CO2 and methanol over CeO2: Role of copper as dopant and the use of methyl trichloroacetate as dehydrating agent

The effect of copper as dopant on ceria (CeO2) was investigated in the direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol. Ceria with different copper loadings (0.02 and 0.5 wt%) was synthesized using the dry impregnation method and characterized by H2-TPR, XRD, EPR, UV–VIS/DRS, acid-base properties and N2 physisorption. CeO2 with 0.02 wt% of Cu showed the highest catalytic activity and selectivity to DMC, mostly due to its basic sites, associated with the presence of oxygen vacancies. Higher Cu concentration (0.5 wt%) promotes dehydrogenation, favoring the formation of methyl formate as the main product. Pure CeO2 also produced dimethoxymethane as by-product. To circumvent the thermodynamic limitations of the reaction, methyl trichloroacetate was tested as dehydrating agent, showing superior performance than 2-cyanopyridine, due to its higher reactivity toward hydrolysis.

Synthesis of Functionalized Polytriazoles via One‐Pot Sequential Copper‐Catalyzed Azide–Alkyne [3+2] Cycloaddition and Atom Transfer Radical Addition (ATRA)

AbstractAs a continuing effort of expanding the scope of catalyst regeneration in the presence of environmentally benign reducing agents, one‐pot sequential azide–alkyne [3+2] cycloaddition and atom transfer radical addition (ATRA) reactions were performed via in situ reduction of copper(II) by ascorbic acid. The formation of functionalized triazoles was achieved utilizing a ligand‐free catalytic system for the cycloaddition between tripropargylamine and vinylbenzyl azide and subsequent addition of tris(2‐pyridyl)methylamine (TPMA) ligand in the ATRA step. With this strategy, reactions with carbon tetrachloride and carbon tetrabromide proceeded efficiently providing the desired triazoles in nearly quantitative yields (>90 %) using 10 mol % of copper. Sequential azide–alkyne [3+2] cycloaddition and ATRA reactions were also extended to less active alkyl halides such as methyl trichloroacetate, methyl dichloroacetate and dichloroacetonitrile. The corresponding products were obtained in modest yields (50–80 %). The presented methodology enables efficient synthesis of functionalized polytriazoles, which could have a potential use as chelating agents for a variety of transition metals.

Electrosynthesis of cyclopropanes at the electrolysis of solutions of methyl esters of Di- and trichloroacetatic acids in aprotic media in the presence of acrylonitrile

The potentiostatic (galvanostatic) electrolysis of methyl esters of trichloroacetic acid on mercury (steel) cathodes in the cathodic compartment of a diaphragm cell in the presence of acrylonitrile affords a mixture of two stereoisomers of methyl ester of 1-chloro-2-cyanocyclopropanecarboxylic acid. The process involves a stage of dehalogenation of the original methyl ester followed by the reaction of the formed anion with acrylonitrile and proceeds more efficiently on a mercury cathode in the dimethylformamide medium with the current efficiency of 94% and the substance yield of 25%. In contrast to methyl trichloroacetate, the electrolysis of methyl dichloroacetate proceeds by an indirect mechanism involving its deprotonation on the steel cathode and by the cleavage of the C-Cl bond on the mercury cathode. In both cases, the acrylonitrile addition leads to formation of the corresponding cyclopropane structures. Moreover, the process is the most efficient on the steel cathode in the MeCN medium. In the latter case, the current efficiency of methyl ester of 1-chloro-2-cyanocyclopropanecarboxylic acid is 31% and substance yield is 41%. Peculiarities of these processes are discussed.

One‐Pot Sequential Azide–Alkyne [3+2] Cycloaddition and Atom Transfer Radical Addition (ATRA): Expanding the Scope of In Situ Copper(I) Regeneration in the Presence of Environmentally Benign Reducing Agent

AbstractOne‐pot sequential reactions involving azide–alkyne [3+2] cycloaddition and atom transfer radical addition (ATRA) catalyzed by [CuII(TPMA)X][X] {X = Br– or Cl–, TPMA = tris(2‐pyridylmethyl)amine} in the presence of ascorbic acid as a reducing agent are reported. Reactions with azidopropyl methacrylate and 1‐(azidomethyl)‐4‐vinylbenzene in the presence of a variety of alkynes [phenylacetylene, (3,4‐difluorophenyl)acetylene, propargyl alcohol, 2‐methyl‐3‐butyn‐2‐ol, methyl propiolate and ethyl propiolate] and alkyl halides (carbon tetrachloride, carbon tetrabromide, ethyl trichloroacetate, methyl trichloroacetate, ethyl dichloroacetate, methyl dichloroacetate, dichloroacetonitrile and 2‐bromopropionitrile) proceeded efficiently to yield highly functionalized (poly)halogenated esters and aryl compounds containing a triazolyl group in the presence of as low as 0.5 mol‐% of the catalyst. It is envisioned that the presented methodology could have further implications in the organic synthesis of functionalized triazoles, which have recently been identified as the lead targets for the screening of potential pharmaceutical drugs.

Immobilized copper catalyst for atom transfer radical addition and polymerization

AbstractA novel multidentate amine grafted on silica gel and magnetic microsphere was prepared. Its chemical structure was confirmed by C13 NMR, XPS and FTIR, and the nitrogen content was determined by elemental analysis. It was also used as a ligand for CuCl and successfully catalyzed the atom transfer radical addition of both carbon tetrachloride (CCl4) to methyl methacrylate and methyl trichloroacetate to styrene, repeatedly. The conversion and purity of the product were determined through gas chromatography and 1H NMR, respectively. The immobilized copper catalyst complex was also used in atom transfer radical polymerization of styrene initiated by 1,1,1,3‐tetrachloro‐3‐phenylpropane and methyl methacrylate initiated by methyl 2‐methyl‐2,4,4,4‐tetrachlorobutyrate, respectively. Although the polymerization took place successfully, it did not proceed in a controlled fashion. Copyright © 2010 John Wiley & Sons, Ltd.

ChemInform Abstract: Reaction of Organo-Silicon Monomers with Methyl Trichloroacetate Under Peroxide and Metal-Complex Initiation.

ChemInform Abstract: Reaction of Organo-Silicon Monomers with Methyl Trichloroacetate Under Peroxide and Metal-Complex Initiation.

A novel oxovanadium(V) complex of 2-(2-butoxyethoxy)ethanolate with high catalytic activities for polymerisation and epoxidation

A dichloro oxovanadium(V) alkoxide complex [VOCl 2(OCH 2CH 2OCH 2CH 2O n Bu)] was synthesised by reaction of VOCl 3 and 2-(2-butoxyethoxy)ethanol in pentane. It was characterised by IR, 1H, 13C and 51V NMR spectroscopy, mass spectrometry and elemental analysis. Single-crystal X-ray diffraction reveals a monomeric complex with all oxygen atoms of the ligand attached to the overall octahedrally coordinated vanadium atom. This complex exhibits remarkably higher activity than VOCl 3 towards ethene polymerisation with diethyl aluminium chloride as co-catalyst and methyl trichloroacetate as promoter. The complex also catalyses the epoxidation of cyclooctene to cyclooctene oxide with tert-butyl hydroperoxide.

Synthesis of Methyl Aziridine-2-Chloro-2-Carboxyletes through Electroreductive Cross Coupling of Methyl Trichloroacetate with Aromatic Imines

Electroreductive of aromatic imine derivatives (1) with methyl trichloroacetate (2) in N,N-dimethylacetamide (DMAc) containing Et4NBr as a supporting electrolyte using an undivided cell equipped with Zn-plates as the electrodes under constant current conditions brought about stereoselective cross coupling to give the corresponding methyl aziridine 2- carboxylates (3) in good to moderate yields.

Electroreductive Cross Coupling of Methyl Trichloroacetate with Schiff Bases to Methyl Aziridine-2-Chloro-2-Carboxyletes

not Available.

Cyclopropane Formation via a Simple Barbier Reaction in DMF.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Cyclopropane Formation via a Simple Barbier Reaction in DMF

Cyclopropanes are prepared in good yields via magnes­ium activation of polyhalomethyl compounds (dichlorodiphenylmethane, methyl trichloroacetate, α,α,α-trichlorotoluene, benzal chloride, benzal bromide) in the presence of activated olefins in DMF.

Selective synthesis of α-chloroepoxides by electroreductive cross-coupling of methyl trichloroacetate with aliphatic aldehydes using reactive metal anodes

It was found in this study that electroreductive cross-coupling of methyl trichloroacetate with aliphatic aldehydes using a reactive metal anode gave the corresponding α-chloroepoxides, useful synthetic intermediates, selectively in good yields. Furthermore, as a synthetic application to organic synthesis, these specific products were subjected to typical reduction with metal hydride reagents and condensation with o-phenylenediamine, showing that they have several interesting reactivities different from those of common epoxides.

Negative Staining of Proteins in Polyacrylamide Gels with Methyl Trichloroacetate

This paper describes a new, sensitive (in the nanogram range), and rapid (two-step) technique for the negative staining of proteins in polyacrylamide gels in the presence or absence of sodium dodecyl sulfate. After separation, gels are incubated with 8% methyl trichloroacetate ester in 38% isopropanol and then washed in water to produce a negative image of colorless proteins against an opaque background. The technique allows unmodified proteins to be recovered for biological studies or transblot for amino acid sequence. Finally, owing to the reversibility of the process, gels can be restained after rapid visualization. For these reasons, negative staining with methyl trichloroacetate should become the method of choice for rapid and sensitive staining of proteins prior to further processing, including stable staining with silver ions.

Thermal decomposition of tetrachloroethylene

Thermal decomposition of tetrachloroethylene was investigated by means of passing air containing tetrachloroethylene vapor through a quartz tube heated at 300 to 940°C. Tetrachloroethylene began to decompose near 400°C and vigorous pyrolysis occurred over 600°C. Complete decomposition was observed at 800°C. Hydrogen chloride and phosgene were detected as decomposition products, presumably because chemical reaction occurs between tetrachloroethylene and water contained in tetrachloroethylene. Organic components identified as pyrolysis products were trichlorobutene, 1,3-dichloro-2-propanone, tetrachlorobutadiene, dichlorocyclopentane/dichloropentene, methyl trichloroacetate, tetrachloroacetone, tetrachloropropene, trichlorocyclopentane/trichloropentene, hexachloroethane, pentachloropropene, hexachloropropene, hexachlorobutadiene.

ChemInform Abstract: Telomerization of Vinylidene Fluoride with CCl4 and R‐CCl3.

AbstractReaction of vinylidene fluoride (II) with tetrachloromethane (Ia), 2,2,2‐trichloroethanol (Ib), or methyl trichloroacetate (Ic), is induced by radical or redox systems to give the telomers (III).

ChemInform Abstract: Reaction of Methyl Trichloroacetate with Vinyltrimethylsilane in the Presence of Metal Carbonyls.

Reaction of methyl trichloroacetate with vinyltrimethylsilane initiated by metal carbonyls yields, depending on the crbonyl, methyl-2,2,4-trichloro-4trimethyl-silyl butyrate [with Mn2(CO)10 or Re2(CO)10], 2,2-dichloro-4-trimethylsilyl-γ-butyrolactone [with Fe(CO)5 or Mo(CO)6], or a mixture of adduct and lactone [with Cr(CO)6 or W(CO)6]. Prior nucleophilic addition of potassium acetate to metal carbonyls of Fe, Mo, Cr, and W suppresses lactonization and an adduct is formed. In the case of Fe(CO)5, HMPA, DMF, and PPh3 react analogously.

Telomerisation du fluorure de vinylidene avec CCl 4 et CCl 3-R

We have studied the telomerization of vinylidene fluoride with carbon tetrachloride, trichloroethanol and methyl trichloroacetate by redox catalysis as well as radical initiation. In all cases, we obtained telomers having the structure : R-CCl 2-(CH 2-CF 2) n-Cl where R=Cl, CH 2OH and CO 2CH3. The first adducts n=1 to 3 have been isolated in each case and analysed by 1H, 13C and 19F NMR spectroscopy. We did not observe any reverse addition of the monomer on itself. We have also compared the two types of initiation for the selectivity of structures and the chain lengths. It should be noted that with CCl 4 in the presence of deficiency of telogen, (often done to increase the DP n) we obtain adducts having the structure : Cl-(CF 2-CH 2) x-CCl 2-(CH 2-CF 2) y-Cl.

Reaction of methyl trichloroacetate with vinyltrimethylsilane in the presence of metal carbonyls

Reaction of methyl trichloroacetate with vinyltrimethylsilane initiated by metal carbonyls yields, depending on the crbonyl, methyl-2,2,4-trichloro-4trimethyl-silyl butyrate [with Mn2(CO)10 or Re2(CO)10], 2,2-dichloro-4-trimethylsilyl-γ-butyrolactone [with Fe(CO)5 or Mo(CO)6], or a mixture of adduct and lactone [with Cr(CO)6 or W(CO)6]. Prior nucleophilic addition of potassium acetate to metal carbonyls of Fe, Mo, Cr, and W suppresses lactonization and an adduct is formed. In the case of Fe(CO)5, HMPA, DMF, and PPh3 react analogously.

Cotelomerization of ethylene and propylene by methyl trichloroacetate

The relative kinetics method was used to study the cotelomerization of ethylene and propylene by methyl chloroacetate. The rate constant for the addition of the electrophilic CCl2CO2CH3radical to ethylene is less than the rate constant for the addition of this radical to propylene by a factor of 2.3. This discrepancy reflects the difference in the polar properties of the monomers.

Zinc(0)–Copper(I) Chloride Promoted Reaction of Methyl Dichlorofluoroacetate with Carbonyl Compounds. A New Efficient Method for the Synthesis of Methyl (Z)-α-Fluoro-α,β-unsaturated Carboxylates

Abstract Methyl dichlorofluoroacetate, easily prepared from methyl trichloroacetate and antimony(III) fluoride, underwent the reductive coupling–elimination reaction with carbonyl compounds in the presence of zinc(0), a catalytic amount of copper(I) chloride, acetic anhydride, and molecular sieves to give the corresponding (Z)-α-fluoro-α,β-unsaturated carboxylic acid methyl esters in high yields.