84928-92-7Relevant academic research and scientific papers
Preparation of an Arenylmethylzinc Reagent with Functional Groups by Chemoselective Cross-Coupling Reaction of Bis(iodoazincio)methane with Iodoarenes
Shimada, Yukako,Haraguchi, Ryosuke,Matsubara, Seijiro
, p. 2395 - 2398 (2015)
Palladium-catalyzed cross-coupling reaction of bis(iodozincio)methane with iodoarenes carrying various functionalities such as ester, boryl, cyano, and halo groups proceeded chemoselectively to give the corresponding arenylmethylzinc species efficiently. The moderate reactivity of the gem-dizinc reagent imparted functional group tolerance to the process. The transformations from iodoheteroarenes were also performed; in the case of iodopyridine derivatives, the nickel-catalyzed reaction gave the corresponding organozinc species efficiently. The obtained arenylmethylzinc species underwent the copper-mediated coupling reaction with a range of organic halides.
Method for separating components in mixture containing methylbenzene, 2-methylthiophene and 3-methylthiophene
-
Paragraph 0052; 0056; 0057; 0058, (2019/12/09)
The invention belongs to the technical field of chemical engineering, and particularly relates to a method for separating components in a mixture containing methylbenzene, 2-methylthiophene and 3-methylthiophene. According to the method, 2-methylthiophene and 3-methylthiophene in the mixture containing methylbenzene, 2-methylthiophene and 3-methylthiophene with very close boiling points are converted into substances 2-chloro-5-methylthiophene and 2,5-dichloro-3-methylthiophene with boiling points greatly different from the boiling point of methylbenzene by adopting a chemical method for the first time; then the components are separated and purified by adopting a rectification method, and the 2-chloro-5-methylthiophene and the 2,5-dichloro-3-methylthiophene are treated by adopting a reduction method and the like to obtain single-component 2-methylthiophene and 3-methylthiophene, so that the methylbenzene, the 2-methylthiophene and the 3-methylthiophene are separated. The method is simple in process, high in product yield and purity, good in separation effect, low in energy consumption and free of emission of three wastes(waste gas, waste water and industrial residues), and is a green separation process.
Catalytic Synthesis of Methylthiophenes
Mashkina,Khairulina
, p. 1794 - 1797 (2019/03/26)
The gas-phase reaction of dimethyl disulfide with thiophene over Co/HZSM-5 catalyst in a helium medium under atmospheric pressure at 250–350°C gave a mixture of mono-, di-, tri-, and tetramethylthiophenes with an overall selectivity of 94–96%.
Photochemistry of furyl- and thienyldiazomethanes: Spectroscopic characterization of triplet 3-thienylcarbene
Pharr, Caroline R.,Kopff, Laura A.,Bennett, Brian,Reid, Scott A.,McMahon, Robert J.
, p. 6443 - 6454 (2012/05/07)
Photolysis (λ > 543 nm) of 3-thienyldiazomethane (1), matrix isolated in Ar or N2 at 10 K, yields triplet 3-thienylcarbene (13) and α-thial-methylenecyclopropene (9). Carbene 13 was characterized by IR, UV/vis, and EPR spectroscopy. The conform
User-friendly methylation of aryl and vinyl halides and pseudohalides with DABAL-Me3
Cooper, Thea,Novak, Andrew,Humphreys, Luke D.,Walker, Matthew D.,Woodward, Simon
, p. 686 - 690 (2007/10/03)
An extremely technically simple cross-methylation of aryl and vinyl halides and pseudohalides using an air-stable adduct of trimethylaluminium with a Pd(0) catalyst supported by commercially available biarylphosphines gives excellent yields of methylated products (mainly > 95%). Reactions can be run with either 0.5 mol% catalyst or without requiring the exclusion of atmospheric oxygen or the drying of solvents in some cases. A wide variety of functional groups is tolerated including CN, OH, CO2R, CHO and NO2.
Palladium catalyzed cross-methylation of bromoheterocycles with intramolecularly stabilized dimethyl indium reagents
Jaber, Nimer,Schumann, Herbert,Blum, Jochanan
, p. 565 - 567 (2007/10/03)
Although the intramolecularly stabilized [(3- dimethylamino)propyl]dimethylaluminum (1a) fails to undergo palladium-catalyzed cross-coupling with bromopyridines and with bromofuran derivatives, the analogous gallium and indium reagent lb and 1c smoothly c
Direct Carbonylation of Benzyl Alcohol and Its Analogs Catalyzed by Palladium and HI in Aqueous Systems and Mechanistic Studies
Lin, Yong-Shou,Yamamoto, Akio
, p. 723 - 734 (2007/10/03)
Carbonylation of benzyl alcohol, benzyl formate, dibenzyl ether, and benzyl phenylacetate catalyzed by palladium complexes and promoted by hydrogen iodide gives phenylacetic acid in moderate to excellent yields in aqueous systems. Application of the carbonylation process to other arylmethanol analogs provides convenient means to prepare 2-naphthaleneacetic acid, 3-isochromanone, 1,4-benzenediacetic acid, and o-hydroxybenzeneacetic acid. A mechanism for the catalytic reaction is proposed, which involves (1) formation of benzyl iodide by the reaction of benzyl alcohol with HI in situ, (2) oxidative addition of benzyl iodide to palladium(0) to form a benzylpalladium iodide species. (3) CO insertion into the Pd-benzyl bond to form a (phenylacetyl)palladium iodide species. (4) reductive elimination of phenylacetyl iodide, and (5) its hydrolysis into phenylacetic acid. Evidence supporting the mechanism was obtained by examining the properties of benzyl- and (phenylacetyl)palladium iodide and chloride complexes. Formation of benzyl(carbonyl)palladium species and migratory insertion of the benzyl group to CO was confirmed by means of NMR at low temperature under high pressure.
Palladium-catalyzed carbonylation of benzyl alcohol and its analogs promoted by HI in aqueous systems
Lin, Yong-Shou,Yamamoto, Akio
, p. 3747 - 3750 (2007/10/03)
Carbonylation of benzyl alcohol catalyzed by a palladium(0) complex and promoted by hydrogen iodide gives phenylacetic acid in excellent yields in aqueous systems. The catalysis is proposed to proceed through a benzylpalladium species formed by the oxidative addition of benzyl iodide, produced in situ by the interaction of benzyl alcohol with HI, to a Pd(0) species. Application of the carbonylation process to other arylmethanol analogs provided convenient means to prepare 3-isochromanone, 1,4-benzenediacetic acid, 2-hydroxybenzeneacetic acid and 2-naphthaleneacetic acid.
Competitive reactivities of vinylthiyl radicals thermally generated from haloethylenes and hydrogen sulfide
Deryagina,Sukhomazova,Levanova
, p. 662 - 666 (2007/10/03)
Acetylene and its derivatives have been used for the first time as "traps" for vinylthiyl radicals generated in situ from hydrogen sulfide and haloethylenes in gas-phase processes. The competitive reactivity of the vinylthiyl radicals has been studied at 500-570 °C in the presence of two chemical "traps." The efficiency of chemical "traps" for the vinylthiyl radicals decreases in the following sequence: HC≡CPh > HC≡CH > MeC≡CH > CH2=CHCl. Acetylene is a more efficient "trap" for the vinylthiyl radicals than 1,2-dichloroethylene, from which they have been generated. The β-phenylvinylthiyl radicals generated during cothermolysis of halostyrene-hydrogen sulfide-acetylene component ternary systems undergo first of all intramolecular ring closure to give benzothiophene, which is a thermodynamically favorable system; the reaction of these radicals with acetylene and its derivatives occurs much more slowly than heterocyclization. Phenylacetylene is a more efficient "trap" than acetylene. α-Phenylvinylthiyl radicals mostly react with acetylene to yield 2-phenylthiophene.
