Gagik Ghazaryan

Bio: Gagik Ghazaryan is an academic researcher from University of Rostock. The author has contributed to research in topics: Regioselectivity & Chemical synthesis. The author has an hindex of 3, co-authored 5 publications receiving 65 citations.

3-Methoxalylchromone—a novel versatile reagent for the regioselective purine isostere synthesis

Abstract: The first synthesis of 3-methoxalylchromone was described. The reaction of the latter with electron-rich aminoheterocycles afforded a set of heteroannelated pyridines bearing a CO2Me substituent located at the α-position of the pyridine core.

3-(Dichloroacetyl)chromone;A New Building Block for the Synthesis of Formylated Purine Isosteres:Design and Synthesis of Fused α-(Formyl)pyridines

Abstract: The first synthesis of 3-(dichloroacetyl)chromone from 3-(dimethylamino)-1-(2-hydroxyphenyl)propen-1-one and dichlo- roacetyl chloride is described. The reaction of electron-rich amino- heterocycles with 3-(dichloroacetyl)chromone provides a set of diverse fused pyridines bearing the CHCl2-substituent at the a-posi- tion of the pyridine core. Subsequent hydrolysis leads to the forma- tion of annulated a-(formyl)pyridines.

E/Z-Selective Synthesis of Alkylidene-3-oxo-3H-isobenzofurans by Reaction of Silyl Enol Ethers with Phthaloyl Dichloride

Abstract: The reaction of silyl enol ethers with phthaloyl dichloride afforded alkylidene-3-oxo-3H-isobenzofurans with very good E/Z-selectivity.

Synthesis of Dichloromethyl-Substituted Salicylates and Pyran-4-ones by Cyclocondensation of 1,3-Bis(silyloxy)-1,3-butadienes with 1,1-Dimethoxy-4,4-dichlorobut-1-en-3-one: Control of the C,C- and C,O-Regioselectivity by the Choice of Lewis Acid.

Abstract: The TiCl4-mediated formal [3+3] cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 1,1-dimethoxy-4,4-dichlorobut-1-en-3-one afforded a variety of functionalized 6-dichloromethyl-4-methoxysalicylates with very good regioselectivity. Some of the products were transformed into 6-formyl-4-methoxysalicylates. The employment of Me3SiOTf instead of TiCl4 resulted in a change of the regioselectivity and in the formation of functionalized 2-(dichloromethyl)pyran-4-ones.

Aminoazole-Based Diversity-Oriented Synthesis of Heterocycles.

Abstract: The comprehensive review contains the analysis of literature data concerning reactions of heterocyclization of aminoazoles and demonstrates the application of these types of transformations in diversity-oriented synthesis. The review is oriented to wide range of chemists working in the field of organic synthesis and both experimental and theoretical studies of nitrogen-containing heterocycles.

Cobalt-catalyzed 1,4-hydrovinylation of allylsilane and allylboronic esters for the synthesis of hydroxy-functionalized 1,4-dienes.

Abstract: The cobalt(I)-catalyzed 1,4-hydrovinylation reaction of allyl trimethylsilane and allyl pinacol boronic ester with symmetrical and unsymmetrical 1,3-dienes generates building blocks for the in situ allylboration or the Lewis acid induced allylation reaction utilizing the corresponding allyl silane derivatives. The products of these three-component reactions are hydroxy-functionalized 1,4-dienes which can be used for the synthesis of pyranones. An alternate reaction sequence for the synthesis of the hydroxy-functionalized 1,4-dienes by performing the allylation first followed by the cobalt-catalyzed 1,4-hydrovinylation is also possible. Accordingly, polyfunctionalized complex structures can be generated by both approaches in a convergent fashion.

One-pot, three-component synthesis of 7-azaindole derivatives from N-substituted 2-amino-4-cyanopyrroles, various aldehydes, and active methylene compounds.

Abstract: An efficient and practical route to 7-azaindole framework has been developed by one-pot, three-component cyclocondensation of N-substituted 2-amino-4-cyanopyrroles, various aldehydes, and active methylene compounds in ethanol or acetic acid at reflux. Reactions involving tetronic acid, indane-1,3-dione, dimedone, and 5-phenylcyclohexane-1,3-dione gave carbocyclic fused 7-azaindoles, whereas Meldrum’s acid, benzoylacetonitrile, and malononitrile resulted in the highly substituted 7-azaindole derivatives, making this strategy very useful in diversity-oriented synthesis (DOS).