Reaction of 2- and 4-(Acetoxymercuriomethyl)-1-phenylquinolinium Perchlorates with Sodium Ethoxide

Russian Journal of Organic Chemistry -     

Stereoselective synthesis of tri- and tetrasubstituted tetrahydropyrans from <Emphasis Type="Italic">syn</Emphasis>- and <Emphasis Type="Italic">anti</Emphasis>-1-R-2-(4-bromophenyl)-5-methylhex-4-en-1-ols and some chemical transformations of the products

Tri- and tetrasubstituted tetrahydropyranes fused to one and two heterocycles with various functional groups (COOEt, Br, MeC=CH₂) were synthesized in stereoselective fashion by reactions of syn- and anti-1-R-2-(4-bromophenyl)-5-methylhex-4-en-1-ols (R = Bu, PhCH₂) with trifluoromethanesulfonic acid, aldehydes in the presence of boron trifluoride–diethyl ether complex (Prins reaction), and salicylaldehydes in the presence of trimethyl orthoformate and p-toluenesulfonic acid. The obtained compounds were brought into Suzuki coupling with thiofen-2-ylboronic acid, hydrolysis, and reduction of the ester group with lithium tetrahydridoaluminate. The resulting carboxylic acid was converted to carboxamide, and the alcohol was oxidized to aldehyde which was converted to oxime. The steric configuration of substituents remained unchanged in all chemical transformations.     

Synthesis of anti-2-aryl-4-en-1-ols from the corresponding syn isomers

Russian Journal of Organic Chemistry - Stereoselective synthesis of anti-2-aryl-4-en-1-ols from the corresponding syn isomers was accomplished with 71–83% yields via the Mitsunobu reaction.     

Synthesis and properties of bis(pyridylmethylene)mercury derivatives

The action of ammonia on - and -monomercurimethylenePyrylium perchlorates gave bis(pyridylmethylene)mercury derivatives, which undergo decomposition to the corresponding pyridine derivatives and mercuric chloride.See [1] for our preceding communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 887–888, July, 1981.     

Blocking sets of Rédei type in projective Hjelmslev planes

In this paper, we introduce Rédei type blocking sets in projective Hjelmslev planes over finite chain rings. We construct, in Hjelmslev planes over chain rings of nilpotency index 2 that contain the residue field as a proper subring, the Baer subplanes associated with this subring as Rédei type blocking sets. Two further examples of Rédei type blocking sets are given for planes over Galois rings generalizing familiar constructions in projective planes over finite fields.     

Stereodirected reactions of salicilaldehyde derivatives with <Emphasis Type="Italic">tert</Emphasis>-butyl 3(4)-hydroxy-2(3)-(3-methylbut-2-enyl)- piperidine-1-carboxylates as an efficient preparation procedure of tetrahydropyran derivatives fused with a piperidine ring

Reaction of salicilaldehyde and its derivatives with unsaturated cis-, trans-alcohols of the piperidine series in the presence of methyl orthoformate and p-toluenesulfonic acid led to the formation of a new heterocyclic system connecting four fuzed rings (two tetrahydropyrans, a piperidine, and an aromatic ring), 6,6-dimethyl-6а,7,7а,8(9),10,11,11а,12а-octahydrochromeno[3′,4′:5,6]pyranо[3,2-с(b)]pyridine.     

In Vitro Antioxidant,Antitumor and Photocatalytic Activities of Silver Nanoparticles Synthesized Using Equisetum Species: A Green Approach

The ethanolic extracts of three Equisetum species (E. pratense Ehrh., E. sylvaticum L. and E. telmateia Ehrh.) were used to reduce silver ions to silver nanoparticles (AgNPs). The synthesized AgNPs were characterized using UV-Vis spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) measurements. FTIR data revealed the functional groups of biomolecules involved in AgNPs synthesis, such as O-H, C-H, C=O, C-O, and C-C. EDX spectroscopy was used to highlight the presence of silver, while DLS spectroscopy provided information on the mean diameter of AgNPs, that ranged from 74.4 to 314 nm. The negative Zeta potential values (−23.76 for Ep–AgNPs, −29.54 for Es–AgNPs and −20.72 for Et–AgNPs) indicate the stability of the obtained colloidal solution. The study also focused on establishing the photocatalytic activity of AgNPs, which is an important aspect in terms of removing organic dyes from the environment. The best photocatalytic activity was observed for AgNPs obtained from E. telmateia, which degraded malachite green in a proportion of 97.9%. The antioxidant action of the three AgNPs samples was highlighted comparatively through four tests, with the best overall antioxidant capacity being observed for AgNPs obtained using E. sylvaticum. Moreover, the biosynthesized AgNPs showed promising cytotoxic efficacy against cancerous cell line MG63, the AgNPs obtained from E. sylvaticum L. providing the best result, with a LD₅₀ value around 1.5 mg/mL.     

Resonant Photon Drag of Dipolar Excitons

The theory of the photon drag of dipolar excitons in double-quantum-well nanostructures is presented. It is shown that the exciton-drag flux density features a resonant behavior if the photon frequency is close to some transition frequency in the discrete exciton spectrum. When the structure is irradiated with polarized light, the resonant enhancement of the drag current occurs when the photon energy coincides with the energy of an excited level of the exciton internal motion and the components of the angular momentum of internal motion in the initial and final states differ by one. The proposed effect can be used to control exciton transport in nanostructures based on a two-dimensional exciton gas.