Andrei A. Tolmachev

Electrophilic substitution as a convenient approach to functionalized N-benzyl-1,4-dihydropyridines

The reactivity of 1-benzyl-3-cyano-1,4-dihydropyridine was studied in reactions with electrophilic reagents based on structural analogy of 1,4-dihydropyridines with enamines. Different 5-functionalized derivatives were obtained by direct electrophilic substitution.

Structural sensitivity in phosphorylation of enamines—derivatives of β-aminocrotonic acid with diphenylchlorophosphine

Abstract The reaction of ‘push–pull’ enamines—derivatives of β-aminocrotonic acid with diphenylchlorophosphine has been investigated. Structural sensitivity of the reaction was found and is discussed.

Addition of some aminoheterocycles to N-benzyl-3-cyanopyridinium chloride

5-Aminopyrazoles react with N-benzyl-3-cyanopyridinium chloride giving 1-benzyl-3-cyano-4-(5-aminopyrazol-4-yl)-1,4-dihydropyridines with high regioselectivity. 5-Aminoisoxazole, 2-aminothiazole and 6-aminouracil react analogously.

A Novel Approach to the Synthesis of [1,2-a]Fused Polymethylenebenzimidazoles

Abstract The synthesis of 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazoles and 7,8,9,10-tetrahydro-6H-azepino[1,2-a]benzimidazoles from cyclic amidines is described.

Synthesis of 7-amino-1-nitro-2-heptanone derivatives

Abstract New N-substituted 7-amino-1-nitro-2-heptanone derivatives have been obtained starting from readily accessible 2-(nitromethylidene)hexahydro-1H-azepine. These compounds have been further used as starting materials for the synthesis of some heterocycles with 5-aminopentyl fragment.

Synthesis and characterization of 4,5-dihydro-1H-pyrazolo[3,4b][1,4]azaphosphinines

1,3,3-Trimethyl-2-(1-R-3-methyl-5-pyrazolyliminoethylidene)indolines were shown to undergo phosphorylation with phosphorus(III) halides at the two nucleophilic carbon centers to give fused 1,4-azaphosphinine ring systems. Chemical properties of the synthesized compounds were characterized. For some representative compounds, detailed NMR spectroscopic investigations were performed, including the determination of 31P, 1H and 31P, 13C coupling constants.

Lactim Ethers in the Synthesis of 1,2-Polymethylene-4-quinazolones

Abstract Condensation of lactim ethers with amides of o-halogeno-substituted aromatic acids was investigated. Derivatives of 5,7,8,9,10,11-hexahydroazepino[1,2-a]quinazolin-5-one and 1,2,3,4-tetrahydropyrrolo-[1,2-a]quinazolin-5-one were obtained.

C-acylation of electron-rich heterocyclic compounds with Kirsanov isocyanate

Pyrroles, indoles, indolizines, and 2-methylfuran are vigorously C-acylated with isocyanatophosphoryl dichloride. The resulting heteroaryl-substituted isocyanatophosphoryl dichlorides provide a convenient access to a variety of products.© 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 343–348, 1999

Phosphorylation of Conjugated Enamines

Abstract Introduction of benzylidene group at α-position of enamines derived from cyclic ketones substantially increases strength of C-P bond thus permitting further syntheses without splitting of the C-P bond. A wide set of phosphorylated derivatives of type (I) were prepared and their properties were studied. Combination of an enamine moiety with other nucleophilic centers such as C or N in a molecule allows to carry out cyclisation giving five- and six-membered phosphorus-containing heterocycles of types (II, III).