Ethyl 3,3-diamino-2-(2-p-tolylpyrimidin-4-yl)acrylate,a new representative of hetarylketene aminals

A new representative of hetarylketene aminals, ethyl 3,3-diamino-2-(2-p-tolylpyrimidin-4-yl)acrylate, was synthesized by the reaction ofp-toluamidine with the condensation product of dimethylformamide dimethyl acetal and the difluoroboron chelate of acetyl(ethoxycarbonyl)ketene (N-benzoyl)aminal. This synthesis is an example of pyrimidine ring assembly using the methodology based on transformations of chelate complexes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1638–1640, September, 1994.This research was partially supported by the International Science Foundation (Grant No. M5QOOO).     

5-Acyl-4-amino-2-phenyl-1,3-oxazin-6-ones

Intramolecular cyclization of acyl(ethoxycarbonyl)keteneN-benzoylaminals in boiling Ph₂O gives 5-acyl-4-amino-2-phenyl-1,3-oxazin-6-ones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1322–1323, July, 1995.This study was financially supported by the Russian Foundation for Basic Research (Grant No. 94-03-08964).     

Acetyl ketene aminals in Nenitzescu reaction

Nenitzescu reaction of acetyl ketene aminals (N,N-acetals) was investigated. The interaction of 2-acetyl-1-amino-1-anilinoethene with benzoquinone gave 3-acetyl-2-amino-7a-hydroxy-1-phenyl-5,7a-dihydro-1H-indol-5-one, which was then transformed into 3-acetyl-2-amino-6-chloro-5-hydroxy-1-phenylindole. The reaction of benzoquinone with 2-acetyl-1-amino-1-benzoylaminoethene led to the corresponding hydroquinone-adduct which was oxidized to 4-acetylamino-5-(2,5-dihydroxyphenyl)-2-phenyloxazole. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 160–165, January, 1999.     

Synthesis of pseudocyanines containing unsaturated groups at the nitrogen atom

A new method for synthesis of 1-[(2-acryloyloxyethyl)- and 1-[(2-propenyl)-2-(2-(1H)-quinolidene)-methyl]-1-ethylquinolinium iodides was proposed. The structures of the dyes obtained were studied by¹H NMR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1122–1124, June, 1995.This work was supported by the Russian Foundation for Basic Research (Project No. 93-02-3467) and the International Science Foundation (Grant RCO 000).     

Synthesis of Spiro Heterocyclic Ketene Aminals

A method is provided for the synthesis of the previously unknown spiro heterocyclic ketene aminals, 3,9-bis(substituted-methylene)-2,4,8,10-tetraazaspiro[5.5]undecane 3 in moderate to excellent yields by cyclocondensation reaction of ketene dithioacetals 1 with tetrakis(aminomethyl)methane 2.     

Regiospecific Synthesis of N-Sulfanilyl Heterocyclic Ketene Aminals

Heterocyclic ketene aminals 1 or 2 reacted with N-acetylsulfanilyl chloride 3 in the presence of sodium hydride to afford N-sulfanilyl heterocyclic ketene aminals 4 or 5 regiospecifically.     

Stereospecific radical addition of isopropanol andn-butanal to (5R)-(l-menthyloxy)furan-2(5H)-one

The radical addition of PrⁱOH andn-butanal to (5R)-5-(l-menthyloxy)furan-2(5H)-one occurs regio- and diastereospecifically at position 4 of the furanone ring.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 345–536, March, 1995.This work was carried out with the financial support of the Russian Foundation for Basic Research (Project No. 93-03-04497).     

Z-Stereoselective Peterson olefination of ketones

A highly-stereoselective method (90 % of theZ-isomer) was developed for the Peterson olefination of ketones with nerylacetone (1) as an example. The method is based on the introduction of a PhS group, which is removed after completion of the reaction, at the ketone C(3) atom.DeceasedFor the perliminary communication, see Ref. 10.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 509–516, March, 1995.The authors are grateful to the Russian Foundation for Basic Research (grant No. 94.03.08904) and the International Science Foundation (grant NGO000) for financial support of this work.     

Synthesis and stereochemical nonrigidity of isomeric Zn(ii)bis-[N-isopropyloxy(mercapto)naphthaldiminates]

Kinetics and reaction mechanisms governing inversion of the tetrahedral configuration at the metal center in the series ofbis-chelate Zn(II) complexes of 3,2-, 1,2-, and 2,1-oxy(mercapto)naphthaldimines, respectively4–6, have been studied with the use of dynamic¹H NMR spectroscopy. A polytopal rearrangement of the diagonal twist type has been found to be an energetically preferable pathway of the inversion reaction for complexes4 and5 with a ZnN₂O₂ coordination site, whereas the inversion reaction for complexes with a ZnN₂S₂ coordination site occurs by an intramolecular dissociation-recombination pathway that involves cleavage of a Zn-N coordination bond. In the case of complexes6, the inversion reaction is governed mainly by intramolecular degenerate ligand exchange reactions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11. pp. 2261–2265, November, 1995.This work was supported by the Russian Foundation for Basic Research (project No. 93-03-18692) and the International Science Foundation (grant No. RNJ 000).     

Synthetic exploitation of halogenated alkenes containing an electron-withdrawing group: synthesis of α-chlorohydrazones and ketene aminals by regiospecific reactions of in situ generated imide chlorides

A concise approach for the construction of ketene aminals and α-chlorohydrazones has been developed. It involves reactions of the regiodefined gem-dihalo nitrovinyl compound of in situ generated imide chlorides in different media with primary arylamines being dependent on the aryl groups. A range of ketene aminals and α-chlorohydrazones are obtained in good to high yields. In addition, α-aminohydrazones are prepared by using α-chlorohydrazones as the precursors.     

Spectral study of the aggregation of benzothiazolic cyanine dyes in solutions and polymolecular layers

The formation ofJ-aggregates of three polymethine dyes in solutions and in Langmuir-Blodgett (LB) polylayers was studied. The dyes formJ-aggregates in mixtures of solvents of different polarity: hexane-chloroform and heptane-chloroform taken in various ratios. The formation ofJ-aggregates in LB polylayers depends on the type of matrix and on the matrix: dye ratio.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 96–99, January, 1995.The authors are grateful to Corresponding Member of the Russian Academy of Sciences M. V. Alfimov for valuable remarks and to Dr. A. I. Tolmachev for kindly donating samples of dyes.This work was financially supported by the Russian Foundation for Basic Research (Project No. 94-03-09182).     

O-Tosylaminobenzaldehyde aminals in the synthesis of 1,3-disubstituted propargylamines,derivatives of 3H-2-vinylidene-3-aminoindoline and quinoline

o-Tosylaminobenzaldehyde aminals react with propargyl alcohol and its phenyl ether on heating in acetonitrile in the presence of CuI to yield 3H-2-vinylidene-3-aminoindoline derivatives. Analogous reactions with phenylacetylene and dimethylethynylcarbinol result in 1,3-disubstituted propargylamines. The possibility of using the latter compounds in synthesis of quinoline derivatives was shown: cyclization of 1-(o-tosylaminophenyl)-1-morpholino-3-phenylprop-2-yne in the presence of H₂SO₄ and KOH gave 2-phenylquinoline and 2-phenyl-4-morpholinoquinoline, respectively. 3H-2-Phenoxymethylvinylidene-3-morpholinoindoline was studied by X-ray diffraction spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2236–2240, November. 1995.     

Synthesis of hexa-, tetra-, and dihydroxanthene derivatives from salicylaldehyde aminals

Salicylaldehyde aminals react with cyclohexanone upon heating to form tetrahydroxanthene derivatives. The structure of one of these derivatives,viz., 5,7-dichloro-4a-morpholino-1,2,3,4-tetrahydro-4aH-xanthene, was established by X-ray diffraction analysis. The scheme of the reaction was suggested, which involves cycloaddition of intermediateo-methylenequinone (from aminal) and enamine (from cyclohexanone). The reactions of salicylaldehyde aminals with enamines that formed from cyclohexanone can successively afford derivatives of hexahydroxanthene, tetrahydroxanthene, and dihydroxanthene. Procedures were developed for the synthesis of these compounds.N-Substituted 4a-amino-7-nitro-1,2,3,4-tetrahydro-4aH-xanthenes were also prepared by the reactions of dialkylammonium 2-formyl-4-nitrophenoxides with the above-mentioned enamines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 959–965, May, 1999.     

Reactions of isomeric 3,6- and 3,5-di-tert-butyl-ortho-benzoquinones with NH3

The interaction of 3,6-di-tert-butyl-ortho-benzoquinone (1) and 3,5-di-tert-butyl-ortho-benzoquinone (2) with NH₃ in water—alcohol medium and with (NH₄)₂CO₃ in a solid phase has been studied. Redox processes with participation of a nucleophile of the medium take place for1, while2 reacts with NH₃ at the carbonyl group with transformation of the quinone imide. The mechanism of redox transformation of1 has been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1789–1793, September, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 94-03-08653).     

Acylation of Heterocyclic Ketene Aminals with Propionyl Chloride

Heterocyclic ketene aminals 1 or 2 reacted with propionyl chloride to give both the mono-N-and C-acylated products 4 and 5 or 6 and 7. While N-methyl heterocyclic ketene aminals 3 reacted with propionyl chloride under the same condition, the reaction took place in complexity. Besides N-and C-acylation, the O-attack and heterocyclic ring cleavage also occurred to give products 8 and 9.     

Complexation and hydrogenation of methionine-containing N-acetyle-dehydrodipeptides

The hydrogenation of the Fe^II complex ofN-Ac-Phe-(S)- or -(R)-Met over a Pd/C catalyst affords mainlyN-Ac-(R)-Phe-(S)-Met orN-Ac-(S)-Phe-(R)-Met, correspondingly. In the reaction of mixed dipeptide complexes with Ca^II and Fe^II the predominance of one of the diastereomers increases from 26 % (for complexes with Fe ions) to 38 %.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 545–546, March, 1994.The work was financially supported by the Russian Foundation for Basic Research (project No. 93-03-4646).     

Chemoselective anti-Markovnikov hydroamination of α,β-ethylenic compounds with amines using montmorillonite clay

The catalytic activity of montmorillonite clays as a catalyst for the hydroamination of α,β-ethylenic compounds with amines was tested. Aniline and substituted anilines reacted with α,β-ethylenic compounds in the presence of catalytic amount of commercially available clay to afford exclusively anti-Markovnikov adduct in excellent yields. Aniline reacted with ethyl acrylate to yield only anti-Markovnikov adduct N-[2-(ethoxycarbonyl)ethyl]aniline (mono-addition product). No Markovnikov adduct (N-[1-(ethoxycarbonyl)ethyl]aniline and double addition product N,N-bis[2-(ethoxycarbonyl)ethyl]aniline were formed under selected reaction conditions. For a better exploitation of the catalytic activity in terms of increased activity and improved selectivity for the mono-addition product, the reaction parameters were optimized in terms of temperature, solvent, reactant mole ratio. Under optimized reaction conditions, montmorillonite clay K-10 showed a superior catalytic performance in the hydroamination of ethyl acrylate with aniline with a conversion of aniline to mono-addition product (almost 100% chemoselectivity) with a high rate constant 0.3414 min⁻¹ compared to the reported protocols. The dependence of conversion of aniline over different types of montmorillonite clays (K-10, K-20, K-30, Al-Pillared clay and untreated clay) has also been discussed. The activities of clay for the hydroamination of different aromatic and aliphatic amines have also been investigated. Under harsh reaction conditions (increased temperature and long reaction time) small amounts of di-addition products were observed. The kinetics data has been interpreted using the initial rate approach model.     

Syntheses of antimony(v) derivatives from trimethyl and triphenylantimony(III), dihydric phenols,andtert-butyl hydroperoxide

Trimethyl and triphenylantimonyo-phenylene dioxides were obtained by the reaction of trimethyl- and triphenylantimony with pyrocatechol in the presence oftert-butyl hydroperoxide in 68 and 81 % yields, respectively. 7,7,7,15,15,15-Hexamethyl-(and phenyl)-6,8,14,16-tetraoxa-7, 15-distibatricyclo[11.3.1.1^9,13]octadeca-1,3,5,9,11,13-hexaenes were synthesized analogously by the reaction with resorcinol (in 79 and 93 % yields, respectively). The use of hydroquinone resulted in polymeric trimethyl- and triphenylantimony hydroquinolates.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 748–751, April, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No 94-03-08846).     

Structure and catalytic mechanism of methane monooxygenase and approaches to its modelling

The mechanisms of activation of O₂ and CH₄ by methane monooxygenase (MMO) are discussed. A new concept for the catalytic cycle of MMO is suggested, and approaches to its chemical modelling are considered.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1011–1020, June, 1995.The author is grateful to Academician A. E. Shilov for interest in this work and helpful discussions. The work was financially supported by the Russian Foundation for Basic Research (Project No. 94-03-08529), International Scientific Foundation (Grant REU000), and INTAS (Project No. 93-315).     

An Efficient One‐Pot Four‐Component Synthesis of Functionalized Imidazo[1,2‐a]pyridines

An efficient one‐pot four‐component protocol for the synthesis of imidazo[1,2‐a]pyridines was developed by condensing ethane‐1,2‐diamine ( 2 ), 1,1‐bis(methylthio)‐2‐nitroethene ( 1 ), aldehydes 3 , and activated methylene compounds in EtOH under reflux conditions (Tables 1–3). The features of this procedure are operational simplicity, good yields of products, in situ preparation of heterocyclic ketene aminals (HKA), and catalyst‐free conditions.