Reactions of (chlorodifluoromethyl)benzene and (chlorodifluoromethoxy)benzene with nucleophilic reagents

Condensation reactions of (chlorodifluoromethyl)benzene and (chlorodifluoromethoxy)benzene with phenoxide and thiophenoxide ions have been performed in DMF or NMP with heating. In these conditions, the reaction between phenylselenide ion and (chlorodifluoromethyl)benzene did not occur. This latter reaction requires an additional visible light irradiation to proceed, as reported by Yoshida et al.     

2-二氟甲氧(硫)基吡啶-5-硼酸频哪醇酯类化合物的合成

以吡啶类化合物作为起始原料,先经二氟甲基化反应在羟基或巯基上引入二氟甲基基团,再用铱催化剂活化吡啶环的C-H并直接引入硼酸频哪醇酯基团,得到目标化合物,其产物结构经1 H NMR、13 C NMR、MS和元素分析确证.该方法具有合成路线较短、反应条件温和、原料廉价易得以及产率较高等优点.     

Reactions of Pyridoxal Derivatives with Phenyl Iso(thio)cyanates

Russian Journal of General Chemistry - The reaction of phenyl isocyanate with pyridoxal is carried out with the participation of hydroxymethyl and phenolic groups with the formation of dicarbamate...     

Reaction of amidophosphites with acrylic acid N-phenylamide

Conclusions Mono- and diamides of phosphorus acid react with the arylamides of,-unsaturated carboxylic acids, with involvement of the carbamido group, to give the corresponding mono- or diamido- N,N-alkylarylcarbamoylalkylphosphonates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 645–646, March, 1971.     

New Bis(thio)-, Tris(thio)-, and Tetrakis(thio)-substituted Quinones from the Reactions of p-Chloranil with Some Thiols and Dithiols

p-Chloranil (1), when reacted with different thiol compounds, namely 1-buthylthiol, cyclohexylthiol, and 2,2-oxydiethanethiol in ethanol in the presence of Na ₂ CO ₃ , yielded the corresponding S-substituted quinone derivatives.     

Transformations of 5-(2-arylethynyl)-2-methyl-2H-tetrazoles under superelectrophilic activation

Reaction of 5-arylethynyl-2-methyl-2H-tetrazoles (acetylene tetrazoles) with arenes under the action of Brønsted superacid CF₃SO₃H or acidic zeolite HUSY CBV-720 gives rise to E-/Z-5-(2,2-diarylethenyl)-2-methyl-2H-tetrazoles, as products of hydroarylation of acetylene bond, in yields up to 98% with predominant formation of E-isomers. Cationic intermediates of these reactions have been studied theoretically by DFT calculations. Addition of CF₃SO₃H to the triple bond of acetylene tetrazoles leads to the corresponding E-/Z-vinyl triflates in high yields. Hydration of triple bond in these tetrazoles in H₂SO₄ results in the formation of 5-(2-aryl-2-oxoethyl)-2-methyl-2H-tetrazoles. Tandem hydroarylation-ionic hydrogenation of acetylene tetrazoles in the systems acid(CF₃SO₃H or AlCl₃)-arene-cyclohexane affords 5-(2,2-diarylethyl)-2-methyl-2H-tetrazoles.     

Ynol esters and alkynyl(phenyl)iodonium chemistry

The author's extensive studies aimed at elaboration of synthetic strategies, and investigation of structure, reactivity pattern, and biological activity of new classes of organic compounds, viz., alkynyloiodonium salts and ynol esters, are reviewed.Based upon a lecture given at the Institute of Organic Chemistry, Moscow, on February 25, 1992, on the occasion of the award of a D.Sc. (honoris causa) and upon two recent related reviews^1,2 on the same topics.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 20–31, January, 1993.     

Reactions of levulinic acid and pseudolevulinic esters with various C-nucleophiles

The reactions of levulinic acid and its pseudo esters, which are readily available from carbohydrate-containing raw materials, with various C-nucleophiles are described. Different reaction pathways were demonstrated depending on the nature of the leaving groups and nucleophiles. For 5-methyl-5-methoxydihydrofuran-2(3H)-one, the reaction was found to proceed by a route giving hept-6-enoic acid derivatives. In contrast, the reaction of 2-methyl-5-oxotetrahydrofuran-2-yl acetate proceeds via intramolecular cyclization to form γ-valerolactone derivatives.     

Reactions of 1,1-dialkylthiosemicarbazides with propiolic acid and its esters

The betaines 2-amino-4,4-dimethyl-²-1,3,4-thiadiazolin-4-io-5-acetates are formed in the reaction of 1,1-dimethylthiosemicarbazides with propiolic acid. 2-Amino-4,4-disubstituted-5-carboalkoxy-methyl-²-1,3,4-thiadiazolinium chlorides, the structure of which has been confirmed by X-ray crystallography, are formed by the reaction of 1,1-disubstituted thiosemicarbazides lower alkyl propiolates in the presence of hydrochloric acid.Translated from Khimiya Geterotsiklicheskikh Soedenenii, No. 12, pp. 1674–1679, 1992.     

Reactions of alkyl 4-hydroxybut-2-ynoates with arenes under superelectrophilic activation with triflic acid or HUSY zeolite: Alternative propargylation or allenylation of arenes,and synthesis of furan-2-ones

Reactions of alkyl 4-aryl(or 4,4-diaryl)-4-hydroxybut-2-ynoates [Ar(H or Ar')(OH)C⁴–C³≡C²–CO₂Alk] with arenes under the action of triflic acid TfOH or HUSY zeolite result in the formation of two main compounds, aryl substituted furan-2-ones or products of propargylation of electron rich arenes. Key reactive intermediates in these transformations are the corresponding O,O-diprotonated forms of starting butynoates, Ar(H or Ar')(⁺OH₂)C⁴–C³≡C²– C(=O⁺H)(OAlk), dehydration of which gives rise to mesomeric propargyl-allenyl cations Ar(H or Ar')(OH)⁴C⁺–C³≡C²–C(=O⁺H)(OAlk) ? Ar(H or Ar')(OH)⁴C = C³ = ²C⁺–C(=O⁺H)(OAlk), having two electrophilic centers on the carbons C4 and C2 respectively. Reactions of these species with arenes at C4 lead to products of arene propargylation, alternatively, reactions at C2 result in allenylation of arenes, followed by further transformation into furan-2-ones. Using quantum chemical calculations by the DFT method, it has been shown that the reactivity of such propargyl-allenyl cations is mainly explained by orbital factors. Plausible reaction mechanism is discussed.     

Reactions of fluorine-containing 3-oxo esters with aldehydes

Fluoroalkylcontaining 3-oxo esters react with aldehydes to form 2-benzylidene-3-fluoroacyl-esters or 4-aryl(alkyl)-3,5-dialkoxycarbonyl-2,6-dihydroxy-2,6-di(fluoroalkyl)tetrahydropyranes depending on the conditions. Ethyl pentafluorobenzoylacetoacetate with benzaldehyde affords 3,5-diethoxy-carbonyl-4-phenyl-2-pentafluorophenyl-7,8,9,10-tetrafluoro-4,5-dihydrobenzo[b]oxacin-6-one.     

BTISA-catalyzed Friedel-Crafts bimolecular cyclization of cinnamic acid under superelectrophilic solvation conditions

Friedel-Crafts bimolecular cyclizations of cinnamic acid and cinnamoyl chloride with aromatic compounds in strong and superstrong acids in present of 1 mol% BTISA were investigated. It was demonstrated that catalytic amounts of this new superacid have essential effect on such type of reactions. Its use makes possible the preparation of indanones with quantitative yields.     

Reactions of 1,3,5-triazinylnitroformaldoximes 3*. Interaction of 1,3,5-triazinylnitroformaldoximes with malonic acid esters

The reaction of 6-R-4-methoxy-1,3,5-triazin-2-ylnitroformaldoximes with dimethyl malonate gives the zwitterionic 4-methoxycarbonyl-3-(4-R-6-methoxy-1,3,5-triazin-2-yl)-4,5-dihydroisoxazol-5-ones. X-ray structural analysis has been carried out on the zwitterionic 4-methoxycarbonyl-3-(4-methoxy-6-piperidino-1,3,5-triazin-2-yl)-4,5-dihydroisoxazol-5-one.     

Reactions of esters of 3-phenyl-3-chloro-2-oxopropionic acid with 2-aminopyridines and 2-aminoquinoline

The reaction of esters of 3-phenyl-3-chloro-2-oxopropionic acid with 2-aminopyridines and 2-aminoquinoline in chloroform at reflux gave derivatives of imidazo[1,2-a]pyridine and imidazo[1,2-a]quinoline in high yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2627–2629, November, 1990.     

A catalytic synthesis of thiosilanes and silthianes: palladium nanoparticle-mediated cross-coupling of silanes with thio phenyl and thio vinyl ethers through selective carbon-sulfur bond activation

Palladium nanoparticles generated in situ from N,N-dimethyl-acetamide (DMA) solutions of PdX(2) (X = Cl(-), OAc(-), OCOCF(3)(-)) or Pd(2)(dba)(3) by reduction with alkyl silanes R(3)SiH (R = Me, Et, i-Pr, t-Bu) are selective catalysts for the cross-coupling of the silanes R(3)SiH with phenyl and vinyl thioethers forming the corresponding thiosilanes and silthianes in high yields and under mild conditions. The method is applicable to phenyl thioglycosides, giving access to thiosilyl glycosides a new class of sugar derivatives.