Fluoroarenes in the synthesis of benzoannulated nitrogen-containing heterocycles

Methods for the synthesis of fluoro-containing benzazoles and benzazines from fluoroarenes (fluoroanilines, fluorobenzoic acids, fluoroacetophenones, fluorophenols, etc.) are described. The potentialities of the most important synthons are considered. Ways of constructing hetero- cycles with fluorine atoms in the annulated benzene fragment are discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 931–966, May, 2008.     

Palladium-catalyzed carboamination in the synthesis of nitrogen-containing heterocycles

An effective method for the stereoselective synthesis of various nitrogen-containing heterocycles by palladium-catalyzed carboamination is discussed. The method application examples to the synthesis of natural structures are presented.     

Catalyzed synthesis of dihydrosilaazaanthracenes-silicon- and nitrogen-containing heterocycles

Conclusions 3-Methyl-4-dimethylphenyl-and 3-methyl-4-diphenylsilylpyridine have been dehydrocyclized over a chromium catalyst (composition 5% chromium (III) oxide, 5% Polirite, 1% potassium oxide, and 89%-Al₂O₃) to give 10,10-diniethyl-and 10-methyl-10-phenyl-9,10-dihydro-10-sila-2-azaanthracene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1905–1906, August, 1984.     

Assembly of nitrogen-containing heterocycles initiated by the aza-Michael reaction

The aza-Michael reaction is considered as the most popular method for the carbon–nitrogen bond formation and the shortest way to β-aminocarbonyl compounds, including β-amino acids and their derivatives. In many cases, conjugate addition of nitrogen-centered nucleophiles to the activated multiple bond triggers a series of cascade transformations being completed by the formation of heterocycles and analogs of natural compounds. The review summarizes the most important advances in the aza-Michael reaction-initiated synthesis of nitrogen-containing heterocycles from unsaturated ketones and enoates.     

Saturated nitrogen-containing heterocycles

A general method for the synthesis of pyrrolidinyland cycloalkanopyrrolidinylpropionic acids by the oxidation of the corresponding heterocyclic alcohols has been developed. Some of those compounds have been converted into the corresponding methyl esters and pyrrolizidin-3-ones. Preliminary pharmacological tests have shown that the pyrrolizidin-3-ones possess a sedative effect.For Communication III, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1051–1055, August, 1970.     

Catalytic synthesis of nitrogen-containing heterocycles (a review)

The process of the catalytic synthesis of a number of nitrogenous heterocyclic compounds based on the utilization of reactions involving the amination of oxygen-containing heterocycles, the dehydration cyclization of amino alcohols, the deamination of di- and polyamines, and the intermolecular dehydration cyclization of glycols with diamines have been considered.     

Saturated nitrogen-containing heterocycles

The method for the preparation of hydroxyalkyl derivatives of pyrrolidine and cyclo-alkanopyrrolidines developed previously has been improved by the replacement of the Raney nickel catalyst by Raney cobalt or partially deactivated palladized carbon. The synthesis of N-methylpyrrolidinylpropanols and cyclopentano[b]pyrrolidinylpropanols and their esterification with some aromatic acids have been performed.For Communication II, see [3].Translated from Khimiya Geterotsiklicheskikh Soedinii, Vol. 6, No. 6, pp. 787–790, June, 1970.     

Multiple nitrogen-containing heterocycles: Metal and non-metal assisted synthesis

A wide variety of biological activities are possessed by N-, O-, and S-containing heterocycles and recently many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and nonmetal became highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of multiple-nitrogen containing five-membered heterocylces in the presence of metal and nonmetal. It describes the formation of five-, six-, and seven-membered heterocyclic rings.     

Stereochemistry of nitrogen-containing heterocycles

The reduction of the - and -isomers of 2-methyl-4-oxooctahydro-1-pyrindine in the presence of Raney nickel and sodium in ethanol has been studied, and four isomers of 2-methyloctahydro-1-pyrindin-4-ol have been obtained. On the basis of an analysis of IR spectra, basicity constants, and the conditions for the reduction of the ketones, the most probable spatial structures have been assigned to all four piperidols.For part XIV, see [1].     

Saturated nitrogen-containing heterocycles. 16. Catalytic synthesis of N-arylperhydroacridines

Catalytic hydroamination of methylene-2,2-dicyclohexanone in the presence of substituted anilines or nitrobenzenes involves the formation of N-arylperhydroacridines. The stereoisomeric composition and yields of the latter are determined by the nature and position of the substituent in the aromatic ring of the aminating agent. The structure of isomeric N-arylperhydroacridines was established from data of ¹³C NMR spectroscopy and x-ray diffraction analysis.For Communication 15, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1094–1100, August, 1993.     

A palladium-catalyzed alkylation/direct arylation synthesis of nitrogen-containing heterocycles

A norbornene-mediated palladium-catalyzed sequence is described in which an alkyl-aryl bond and an aryl-heteroaryl bond are formed in one reaction vessel. The aryl-heteroaryl bond-forming step occurs via a direct arylation reaction. A number of six-, seven-, and eight-membered ring-annulated indoles, pyrroles, pyrazoles, and azaindoles were synthesized from the corresponding bromoalkyl azole and an aryl iodide.     

Fused polycyclic nitrogen-containing heterocycles

Upon treatment with acetic acid, 3-(2-phenyl-1-selenocyanatoethyl)-, 3-(3-phenyl-1-selenocyanatopropyl)quinoxalin-2(1H)-ones and their thio analogs undergo intramolecular condensation to form selenazolo-and thiazolo[3,4-a]quinoxalines. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2055–2058, October, 2007.     

Saturated nitrogen-containing heterocycles. 11. The synthesis and structural studies of octahydroindolylalkanols

A catalytic synthesis was carried out for 3-(1-R-2-octahydroindolyl)alkanols using nickel promoted by ruthenium, Raney nickel, and Raney cobalt previously treated with acetic acid. An x-ray diffraction structural study of the acid tartrate of 3-(1-methyl-2-octahydroindolyl)-1-propanol gave the absolute configuration and conformational and structural features of the cation and tartrate anion.For Communication 10, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 66–70, January, 1985.     

A new synthesis of nitrogen-containing heterocycles by means of organoaluminum reagents

Nitrogen-containing heterocycles can be derived in synthetically good yields from a variety of carbocyclic frameworks via the successive rearrangement-alkylation sequence of hydroxylamine carbonates with trialkylaluminums.     

Aza-1,3-butadienes in synthesis of nitrogen-containing six-membered heterocycles (review)

We review and generalize literature data in recent years on application of heterodiene synthesis to obtain azines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1307, October, 1992     

A facile synthesis of 4-acylamino-tetrahydroindazoles via the Ritter reaction

A new route toward 4-acylamino- and 4-amino-substituted tetrahydroindazoles is disclosed. The title compounds are obtained in good to excellent yields in the Ritter reaction between 4-hydroxy-tetrahydroindazoles and various nitriles. The reactivity of the tetrahydroindazole-derived carbenium ion is both sufficiently high to react with trichloroacetonitrile and sufficiently selective to resist the azide functionality within its structure. The present approach adds a method to the toolbox of tetrahydroindazole chemistry and facilitates the structural modifications of the scaffold, which has found important applications in medicinal chemistry.     

Organocatalytic synthesis of amides from nitriles via the Ritter reaction

A simple, inexpensive, environmentally friendly, and efficient route for the synthesis of a wide variety of amides in high yields via the Ritter reaction of alcohols with nitriles has been demonstrated. Pentafluorophenyl ammonium triflate (PFPAT) is used as an organocatalyst and is air-stable, cost-effective, easy to handle, and easily removed from the reaction mixtures.     

The Mannich reaction in the synthesis of N,S-containing heterocycles

Reactions of 6-aryl-5-cyano-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidines with formaldehyde and primary amines gave earlier unknown 3,4-dihydro-2H,6H-pyrimido[2,1-b]-[1,3,5]thiadiazine derivatives in 58–94% yields. In boiling AcOH, these pyrimidothiadiazines underwent the retro-Mannich reaction leading to the starting pyrimidine-2-thiones. The structure of 3-(4-ethoxyphenyl)-6-oxo-8-phenyl-3,4-dihydro-2H,6H-pyrimido[2,1-b][1,3,5]thiadiazine-7-carbonitrile was studied by X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1384–1387, July, 2007.