Natalya V. Sigay

Bio: Natalya V. Sigay is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Alkylation & Stereocenter. The author has an hindex of 3, co-authored 6 publications receiving 34 citations.

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy.

Abstract: An effective and highly regio- and diastereoselective one-pot method for the synthesis of new polynuclear dispiroheterocyclic systems with five stereogenic centers (dispiro[imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-6,3′-pyrrolidine-2′,3′′-indoles]) comprising pyrrolidinyloxindole and imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine moieties has been developed. The method relies on a 1,3-dipolar cycloaddition of azomethine ylides generated in situ from isatin derivatives and sarcosine to 6-benzylideneimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7-diones.

Synthesis, S-alkylation, and fungicidal activity of 4-(benzylideneamino)thioglycolurils

Abstract: A series of 1,3-disubstituted 4-benzylideneamino-5-thioxohexahydroimidazo[4,5-d]imidazol-2(1H)-ones (thioglycolurils) was synthesized via the reaction of 5,7-disubstituted 3-thioxoperhydroimidazo[4,5-e]-1,2,4-triazin-6-ones with hydroxy-, alkoxy-, and fluorocontaining benzaldehyde derivatives. An alkylation of the obtained thioglycolurils with methyl iodide or 4-bromobenzyl bromide provided the corresponding 6-benzylideneamino-5-alkylsulfanyl-3,3a,6,6a-tetrahydroimidazo[4,5-d]imidazol-2(1H)-ones. The fungicidal activity of some synthesized compounds against pathogens causing diseases of agricultural crops was studied.

Functionally substituted aromatic aldehydes as reagents in the synthesis of new substituted thioglycolurils

Abstract: Simple approach to the synthesis of 2-(4(2)-(((4,6-dialkyl-5-oxo-2-thioxohexahydroimidazo[4,5-d]imidazol1(2H)-yl)imino)methyl)phenoxy)acetates or acetamides (new substituted thioglycolurils) based on the reaction of 5,7-dialkyl-3-thioxoperhydroimidazo[4,5-e]-1,2,4-triazine-6-ones with functionally substituted aromatic aldehydes has been developed. Synthesized thioglycolurils with acetate function can undergo further simple transformation to the corresponding acetamides.

Synthesis of 1,3-dialkyl-4-[(arylmethylidene)amino]glycolurils

Abstract: A method for the synthesis of 1,3-dialkyl-4-[(arylmethylidene)amino]glycolurils was developed based on nucleophilic substitution of the sulfur atom with the oxygen atom in the corresponding thioglycolurils via alkylation of the latter followed by acid hydrolysis of alkylsulfanyl derivatives of thioglycolurils, both with the isolation of alkylsulfanyl intermediates and by the one-pot method. The structure of the synthesized compounds was confirmed by X-ray structural analysis of several examples.

Classical and interdisciplinary approaches to the design of organic and hybrid molecular systems

Abstract: This review summarizes the recent advances in the construction of organic and hybrid systems having considerable potential for practical applications in pharmacology, medicine, materials science, petrochemistry, and chemistry of high-energy compounds. The methodological classification of the approaches into classical and interdisciplinary is proposed. Examples of the efficient application of these approaches for investigating complex molecular systems, as well as for developing new methods of synthesis are given.

Engaging Isatins in Multicomponent Reactions (MCRs) - Easy Access to Structural Diversity.

Abstract: Multicomponent reactions (MCRs) are a valuable tool in diversity-oriented synthesis. Its application to privileged structures is gaining relevance in the fields of organic and medicinal chemistry. Isatin, due to its unique reactivity, can undergo different MCRs, affording multiple interesting scaffolds, namely oxindole-derivatives (including spirooxindoles, bis-oxindoles and 3,3-disubstituted oxindoles) and even, under certain conditions, ring-opening reactions occur that leads to other heterocyclic compounds. Over the past few years, new methodologies have been described for the application of this important and easily available starting material in MCRs. In this review, we explore these novelties, displaying them according to the structure of the final products obtained.

Oxoindolinylidene Derivatives of Thiazolidin-4-ones: Methods of Synthesis and Biological Activity (Review)

Abstract: We offer a review on synthetic methods and biological activity data for oxoindolinylidene derivatives of thiazolidin-4-ones, including heteroannelated examples of such compounds, published between 1967 and 2014.

The influence of substituents on the reactivity and cytotoxicity of imidazothiazolotriazinones

Abstract: A series of tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H, 6H)-diones were synthesized via the reaction of imidazotriazinethiones and bromoacetic acid followed by condensation with isatins. Amidine skeletal rearrangement of 3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7 (1H, 6H)-diones into 1,3a,4,9a-tetrahydroimidazo[4,5-e]thiazolo[2,3-c]-1,2,4-triazine-2,8 (3H, 7H)-diones under KOH treatment has been studied. The influence of substituents at positions 1,3,3a,6,9a of imidazothiazolotriazine on the ability to undergo rearrangement was analyzed based on experimental data and theoretical calculations. Both imidazothiazolo[3,2-b]triazines and their rearrangement products were evaluated for their cytotoxic activity against rhabdomyosarcoma, A549, HCT116 and MCF7 human cancer cell lines by MTT assay. Among the derivatives, 1,3-diethyl-6-[1-(2-propyl)-2-oxoindolin-3-ylidene]-3,3a,9,9a-tetrahydroimidazo [4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H, 6H)-dione 4i was found to have the highest antiproliferative activity toward the tested cell lines (4i: $$\hbox {IC}_{50} = 2.20$$ , 2.29, 0.47 and $$3.11\,{\upmu }\hbox {M}$$ , respectively). The $$\hbox {IC}_{50}$$ value of compound 4i against normal human embryonic kidney cells HEK293 was $$19.34\,{\upmu }\hbox {M}$$ , which appeared to be 6–41-fold higher than $$\hbox {IC}_{50}$$ values of 4i against human cancer cells.