Mikhail M. Krayushkin

Photoinduced skeletal rearrangement of diarylethenes comprising oxazole and phenyl rings.

A novel photochemical rearrangement of diarylethenes bearing oxazole and benzene derivatives as aryl moieties that results in the formation of polyaromatic systems was investigated. The mechanism of the transformation includes photocyclization, sequential [1,9] and [1,3]-hydrogen shifts, as well as a lateral oxazole ring-opening process. It was shown that this reaction can be an effective synthetically preparative method for the preparation of naphthalene (polyaromatic) derivatives.

Design, Synthesis and Structure-activity Studies of Rhodanine Derivatives as HIV-1 Integrase Inhibitors

Raltegravir was the first HIV-1 integrase inhibitor that gained FDA approval for use in the treatment of HIV-1 infection. Because of the emergence of IN inhibitor-resistant viral strains, there is a need to identify innovative second-generation IN inhibitors. Previously, we identified 2-thioxo-4-thiazolidinone (rhodanine)-containing compounds as IN inhibitors. Herein, we report the design, synthesis and docking studies of a series of novel rhodanine derivatives as IN inhibitors. All these compounds were further tested against human apurinic/apyrimidinic endonuclease 1 (APE1) to determine their selectivity. Two compounds showed significant cytotoxicity in a panel of human cancer cell lines. Taken together, our results show that rhodanines are a promising class of compounds for developing drugs with antiviral and anticancer properties.

General Photoinduced Sequential Electrocyclization/[1,9]-Sigmatropic Rearrangement/Ring-Opening Reaction of Diarylethenes.

A novel and efficient photochemical transformation of diarylethenes comprising a five-membered heterocyclic ring and phenyl moiety is described. This reaction provides a simple method for the preparation of functionalized naphthalene derivatives via photorearrangement reaction of diarylethenes, and the process is characterized by high efficiency that was determined by NMR monitoring. Some mechanistic aspects of this process have been also explored. It was found that the reaction includes tandem transformation of three basic processes: the photocyclization of the hexatriene system, [1,9]-sigmatropic rearrangement, and heterocyclic ring opening. Diarylethenes with different heterocycle moieties (thiophene, benzo[b]thiophene, furan, indole, imidazole, thiazole, oxazole, pyrazole) have been involved into this process, and the target naphthalenes with good yields have been obtained. The opportunity for use in the transformation of diarylethenes with different heterocyclic residues permits synthesis of naphthalenes with desired functional groups. The general character and high efficiency of the reaction promise that the transformation can be an effective synthetic route for the annulation of benzene rings to various aromatic systems, including heterocycles.

Syntheses of Photochromic Dihetarylethenes

Publisher Summary This chapter focuses on the methods that are used for the synthesis of photochromic dihetarylethenes, in which both heterocycles are in vicinal positions at the double bond of cyclopentene, perfluorocyclopentene, and various heterocyclic moieties. The photocyclization of stilbenes and dihetarylethenes (DHEs) is accompanied by cis–trans isomerization, and the trans isomers do not give a cyclized form. Thus, products with a fixed cis conformation, in which the thienyl or benzothienyl moieties are linked to the double bonds of perfluorocyclopentene, maleic anhydride, and maleimide, are synthesized. Photochromes containing such “bridges” possess not only thermal irreversibility but also high fatigue resistance, amounting in some cases, to 10,000 cycles. These properties combined with other useful physicochemical characteristics offer ample opportunities for the use of dihetarylethenes in nonlinear optics, optical memory devices, as photoswitches, linkers, display elements, etc. Some dihetarylethenes, such as bis(indolyl)furan-2,5-diones that were covered by patents as typical photochromes have a broad spectrum of biological activities. This chapter discusses the synthesis of perfluorocyclopentene-bridged dihetarylethenes, dithienylperhydrocyclopentenes, and their heteroanalogs, synthesis of dithienyl photochromes containing a maleic anhydride fragment as the ethene-bridge and diarylmaleimides containing optically active dihetarylethenes.

Synthesis and reactivity of 1-aryl-9H-thieno[3,4-b]chromon-9-ones

Methods were developed for the synthesis of 1-aryl-9H-thieno[3,4-b]chromon-9-ones based on the reaction of bromo and dibromo derivatives of 2-methyl-4H-chromon-4-one with thioacetamide in DMF. The thienochromones were modified and their fluorescence properties were studied. Bis(thienochromones) were synthesized by the reaction of thienochromones with ketoaldehydes.

A new redox system: Trichloromethylarene — pyridine base. On the mechanism of the synthesis of N-(4-pyridyl)pyridinium dichloride

Abstract A redox reaction of trichloromethylarenes with pyridines results in respective N-(α-chloroarylmethyl)-substituted pyridinium chlorides which give on hydrolysis aromatic aldehydes and 4-chloropyridines or 1,4′-bipyridinium salts.

Hydrazones derived from thiooxamohydrazides and 3-formyl-4-hydroxycoumarin: synthesis, structures, and fragmentation

Novel hydrazones were obtained from thiooxamohydrazides and 3-3-formyl-4-hydroxycoumarin. According to data from NMR spectroscopy and X-ray diffraction, the coumarin fragment in the compounds obtained exists as 4-hydroxycoumarin or chromane-2,4-dione. When dissolved in dimethyl sulfoxide, these hydrazones undergo fragmentation into derivatives of 1,3,4-thiadiazole and 4-hydroxycoumarin.

Photochromic and irreversible photofluorescent organic materials for 3D bitwise optical memory

This paper presents latest own results in the development of reversible photochromic and irreversible photofluorescent polymer systems providing fabrication of multilayer recording media for 3D optical memory with super high information capacity. It was shown that synthesized thermal irreversible photochromic diarylethenes into plastic binders allow to prepare photochromic polymer layers providing nondestructive refractive read-out of optical information. These photochromic polymer layers were used for preparation of six-layer recording media tested with the positive results using the framed optical device. This device imitated layer-by-layer writing, erasure and read-out of optical signals. Experimental evidences for making photochromic polymer layers based on a mixture of photochromic diarylethene and dye — phosphor with nondestructive fluorescent read-out are presented too. Polymer systems based on light-sensitive chromones manifest an irreversible photochemical transformations of these non-fluorescing compounds into the fluorescent products under UV irradiation. Received results open perspectives for making multilayer optical discs for bitwise working (based on photochromic systems) and archival (based on irreversible photofluorescent systems) optical memory with information capacity more 1 TB.

Synthesis and photoinduced fluorescence of 3-(2-hetarylethenyl)chromen-2-ones

Abstract3-(2-Hetarylethenyl)chromen-2-ones were synthesized for the first time, following two different schemes, and their spectral and photochemical properties were studied. The title compounds were found to undergo both reversible and irreversible photoinduced transformations which are accompanied by considerable change of the fluorescence pattern.

Three-Component Condensation of 2,4-Diaminoselenazole with Aldehydes and Meldrum’s Acid: Synthesis of 7-Aryl(alkyl)-Substituted 2-Amino-6,7-dihydro-4H-selenazolo[4,5-b]pyridin-5-ones

A method for the synthesis of 7-aryl(alkyl)-substituted 2-amino-6,7-dihydro-4H-selenazolo [4,5-b]pyridin-5-ones 5 based on three-component condensation of in situ–generated 2,4-diaminoselenazole 7 with aromatic (aliphatic) aldehydes 9 and Meldrums acid 10 was developed.