Alexander A. Titov

A novel multi-component approach to the synthesis of pyrrolo[2,1-a]isoquinoline derivatives

A route towards pyrrolo[2,1-a]isoquinolines through a 3CR of 1-aroyl dihydroisoquinolines, activated alkynes and alcohols has been developed.

Synthesis of 6-aryl-Substituted Azocino-[5,4-b]indoles from 1-aryl-Substituted 2-Ethyltetrahydro-β-Carbolines

We optimized the reaction of tetrahydropyridine ring expansion in 1-aryl-substituted tetrahydro-β-carbolines by the action of activated alkynes and achieved higher than 70% yields of the target indoloazocines. The substituents in the 1-aryl ring and at the indole nitrogen atom were shown to affect the rate and selectivity of this transformation.

Synthesis of pyrrolo[1,2-a][1,6]benzodiazonines from pyrrolo[1,2-a][1,4]benzodiazepines and alkynes containing electron-acceptor substituents

It has been established that the reaction of pyrrolo[1,2-a][1,4]benzodiazepines with activated alkynes gives pyrrolo[1,2-a][1,6]benzodiazonines as the products of diazepine ring expansion. In the case of pyrrolo[1,2-a][1,4]benzodiazepine, substituted with formyl group at the pyrrole ring, both expansion and cleavage of the diazepine fragment can occur.

First synthesis of heterocyclic allenes – benzazecine derivatives

Benzazecines with an allene fragment were prepared for the first time and in high yields via tandem reaction of 1-phenylethynyl-1-methyl(benzyl)-1,2,3,4-tetrahydroisoquinolines with activated alkynes in trifluoroethanol.

Transformations of cotarnine chloride by the action of silver acetylides and alkynes

Three-component reactions of cotarnine chloride with silver acetylides and methyl propiolate or ethynyl methyl ketone in acetonitrile, as well as two-component reactions of 5-phenylethynyl-substituted tetrahydro[1,3]dioxolo[4,5-g]isoquinoline with alkynes in various solvents were studied. Performing them in 2,2,2-trifluoroethanol as the solvent, 10-phenylethynyl-substituted tetrahydro[1,3]dioxolo[4,5-i]-[3]benzazocines were obtained in good yields.

The first synthesis of 6-(phenylethynyl)-substituted tetrahydroazocino[5,4-b]indoles

The reaction of 2-methyl-1-(phenylethynyl)-2,3,4,9-tetrahydro-1Н-β-carboline with activated alkynes in acetonitrile led to the formation of 1-vinyl-substituted β-carbolines and condensed azocines.

Transformation of 4-Substituted Tetrahydro-Pyrrolobenzodiazepines in a Three-Component Reaction With Methyl Propiolate and Indole

The three-component reaction of 4-phenyl-, p-methoxyphenyl-, and thienylpyrrolo[1,2-a][1,4]benzo-diazepines with methyl propiolate and indole in dichloromethane proceeds through opening of the diazepine ring. The major transformation products isolated are substituted pyrroles, namely, 1-(2-aminomethylphenyl)-5-(arylmethyl)-2-(indol-1(3)-yl)pyrroles and 1-(2-aminomethylphenyl)-2-aryl-(indol-3-yl)-methylpyrroles.

Synthesis of azecino[5,4-b]indoles and indolo[3,2-e][2]benzazonines via tandem transformation of hydrogenated indoloquinolizines and indolizines

The reactions of partially hydrogenated indole-fused quinolizines and indolizines with activated alkynes in methanol, acetonitrile, and dichloromethane were studied. The reactions were shown to be accompanied by the cleavage of the bridging C-N bond. Azecino[5,4-b]-indole and indolo[3,2-e][2]benzazonine derivatives were synthesized.

Unusual thermolysis of aza­cyclic allene under microwave conditions: crystal structure of (3RS,3aSR,8RS,8aRS)-methyl 5,6-dimeth­oxy-3a,10-dimethyl-1-phenyl-3,3a,8,8a-tetra­hydro-3,8-(epimino­methano)­cyclo­penta­[a]indene-2-carboxyl­ate from synchrotron X-ray diffraction

The structure of methyl 5,6-dimethoxy-3a,10-dimethyl-1-phenyl-3,3a,8,8a-tetrahydro-3,8-(epiminomethano)cyclopenta[a]indene-2-carboxylate, the product of unusual thermolysis of azacyclic allene under microvawe conditions, was studied by synchrotron X-ray diffraction.

A new approach to alkaloid-like systems: synthesis and crystal structure of 1-(2-acetyl-11-meth­oxy-5,6-di­hydro­[1,3]dioxolo[4,5-g]pyrrolo­[2,1-a]isoquinolin-1-yl)propan-2-one

1-(2-Acetyl-11-methoxy-5,6-dihydro[1,3]dioxolo[4,5-g]pyrrolo[2,1-a]isoquinolin-1-yl)propan-2-one, the product of a domino reaction between cotarnine chloride and acetylacetylene catalysed by copper(I) iodide, was studied by X-ray diffraction.