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Just add water! A range of heterogeneous ‐SO₃H functionalized catalysts were investigated for the first time using the Prins‐Ritter (−)‐isopulegol reaction with benzaldehyde and acetonitrile as a model producing 4‐amido derivatives of octahydro‐2H‐chromenes (as S‐ and R‐diastereomers). A strong effect of water addition prior the reaction on the overall selectivity and the ratio of isomers was found.

На сайте  журнала ChemCatChem (IF 4,495) опубликована статья с участием сотрудников Института:  Н.С. Ли-Жуланова (мнс, ЛНТПС),  д.х.н., проф. РАН К.П. Волчо (гнс, ЛФАФ) и д.х.н., член.-корр. РАН, поф. Н.Ф. Салахутдинова (зав .отделом медицинской химии)

Stereoselectivity Inversion by Water Addition in the −SO₃H‐catalyzed Tandem Prins‐Ritter Reaction for Synthesis of 4‐amidotetrahydropyran Derivatives

Dr. Alexander Yu. Sidorenko,  Nikolai S. Li‐Zhulanov, Päivi Mäki‐Arvela, Thomas Sandberg, Anna V. Kravtsova, Andreia F. Peixoto, Cristina Freire, Konstantin P. Volcho, Nariman F. Salakhutdinov, Vladimir E. Agabekov, Prof. Dmitry Yu. Murzin

Abstract

A range of heterogeneous ‐SO₃H functionalized catalysts including carbon and halloysite nanotubes, commercial K10 clay, Amberlyst‐15 etc. was investigated for the first time using as a model the Prins‐Ritter reaction of (−)‐isopulegol with benzaldehyde and acetonitrile producing 4‐amido derivatives of octahydro‐2H‐chromenes (as (S)‐ and (R)‐diastereomers). A strong effect of water addition prior the reaction on the overall selectivity and the ratio of isomers in the case of heterogeneous and homogeneous (p‐toluenesulfonic acid) catalysis was found for the first time. The yield of the (R)‐diastereomer sharply increased with increasing amount of added water, while the S‐isomer prevailed with a minimum amount of added water. Experimental results and DFT calculations clearly indicate a kinetic control for R‐amide formation. Typically synthesis of 4‐amidooctahydro‐2H‐chromenes requires subzero temperatures and toxic catalysts, which were avoided in the current work. Nevertheless, the yield of the desired products (up to 83 %) at 30 °C after water addition exceeded the values reported previously. Thus, adding water is a simple and a very effective method for controlling both the yield and stereoselectivity of the Prins‐Ritter reaction products under mild conditions.

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В журналу Materials Science and Engineering: C  (IF 4,959) опубликована статья с участием сотрудников Института:  д.м.н. Н.А. Жуковой (внс, ЛФИ), д.б.н. М.В. Хвостова (снс, ЛФИ), к.б.н.А.В. Павловой (нс, ЛФИ) и д.б.н., проф. Т.Г. Толстиковой (завлаб, ЛФИ)

Biodegradable poly(l-lactide)/calcium phosphate composites with improved properties for orthopedics: Effect of filler and polymer crystallinity

Varvara A.Demina, Sergei V. Krasheninnikov, Alexander I. Buzin, Roman A. Kamyshinsky, Natalya V. Sadovskaya, Evgeny N. Goncharov, Natalya A. Zhukova, Mikhail V. Khvostov, Alla V. Pavlova, Tatjana G. Tolstikova, Nikita G. Sedush, Sergei N. Chvalun

Materials Science and Engineering: C Volume 112, July 2020, 110813 ,
Publication Date:March 06, 2020


https://doi.org/10.1016/j.msec.2020.110813

Abstract

Biodegradable poly(l-lactide)/calcium phosphate composites are promising materials for fabrication of bone fixation implants with improved properties. Multistage compounding was proposed as an efficient method for the preparation of biodegradable poly(l-lactide)/calcium phosphate composites with submicron filler dispersion and mechanical characteristics similar to native bone. The improvement of the characteristics is caused both by the filler itself and by the increase of polymer crystallinity due to the nucleation effect. The technique allows to fabricate biodegradable composites with controlled properties by varying concentration and type of the filler as well as degree of PLLA matrix crystallinity. Animal studies revealed that all the composites were biocompatible and non-toxic.

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В журналу Journal of Membrane Science (IF 7,015) опубликована статья с участием сотрудника Института   к.х.н. И.А.Кирилюка (завлаб, ЛАС):

Electrostatic properties of inner nanopore surfaces of anodic aluminum oxide membranes upon high temperature annealing revealed by EPR of pH-sensitive spin probes and labels

Abstract

Anodic aluminum oxide (AAO) membranes are versatile nanomaterials that combine the chemically stable and mechanically robust properties of ceramics with homogeneous nanoscale organization that can be tuned to desirable pore diameters and lengths. The AAO substrates feature high surface area that is readily accessible to large and small molecules, making these nanostructures uniquely suited for many possible applications. Examples include templated self-assembly of macroscopically aligned biological membranes and substrates for heterogeneous catalysis. For further development of such applications, one would like to characterize and tune the electrostatic properties of the inner pore surface as well as the local acidity within the nanochannels. Here, we employed electron paramagnetic resonance (EPR) spectroscopy of a small molecule – ionizable nitroxide – as a reporter of the average local acidity in the nanochannels and the local electrostatic potential in the immediate vicinity of the pore surface. The former was achieved by measuring EPR spectra of this molecular probe diffusing in an aqueous phase confined in the AAO nanochannels while for the latter the nitroxide was covalently attached to the hydroxyl group of the alumina surface. We show that the local acidity within the nanochannels is increased by as much as ≈1.48 pH units vs. the pH of bulk solution by decreasing the pore diameter down to ca. 31 nm. Furthermore, the positive surface charge of the as-prepared AAO could be decreased and even switched to a negative surface charge upon annealing the membranes first to 700 °C and then to 1200 °C. For as-prepared AAO, the local electrostatic potential reaches ψ= (163 ± 5) mV for the nitroxide label covalently attached to AAO and located about 0.5 nm away from the surface. Overall, we demonstrate that the acid-based properties of the aqueous volume confined by the AAO nanopores pores can be tuned by either changing the pore diameter from ca. 71 to 31 nm or by thermal annealing to switch the sign of the surface charge. These observations provide a simple and robust means to tailor these versatile high-surface-area nanomaterials for specific applications that depend on acid-base equilibria.

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В журналу ACS Sustainable Chem. Eng. (IF 6,97) опубликована статья с участием сотрудницы Института   д.х.н. М.В. Еделевой (снс, ЛМР):

No Catalyst Added Hydrogen Peroxide Oxidation of Dextran: An Environmentally Friendly Route to Multifunctional Polymers

Ekaterina V. Pronina, Yuri A. Vorotnikov, Tatiana N. Pozmogova, Anastasiya O. Solovieva, Svetlana M. Miroshnichenko, Pavel E. Plyusnin, Denis P. Pishchur, Ilia V. Eltsov, Mariya V. Edeleva, Michael A. Shestopalov, Olga A. Efremova

ACS Sustainable Chem. Eng. 2020, 8, 13, 5371-5379,
Publication Date:March 16, 2020


https://doi.org/10.1021/acssuschemeng.0c01030

Abstract

The paper demonstrates a “greener” oxidation of dextran polymer of various molecular masses, the component of many industrially and pharmaceutically important materials, by aqueous H₂O₂ in a no catalyst added setting that produced a multifunctional oxidized dextran. Specifically, on the top of common functional groups (hydroxo, carbonyl, and carboxylic acids), the freshly peroxide oxidized dextran had also a significant number of peroxo-groups, which endowed the polymer with significant cytotoxic properties, as demonstrated on a larynx carcinoma cell line. We also have shown that the peroxo-groups could be easily removed in an alkaline media to yield nontoxic oxidized dextran polymers.

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В журналу Bioorganic Chemistry (IF 3,926) опубликована статья с участием сотрудников Института   к.х.н. С.О. Куранова (нс, ЛНТПС ), д.х.н. О.А. Лузиной (внс ЛФАВ) и д.х.н., чл.-корр. РАН, проф.  Н.Ф. Салахутдинова (зав.оделом, ОМХ, завлаб , ЛФАВ):

Exploring bulky natural and natural-like periphery in the design of p-(benzyloxy)phenylpropionic acid agonists of free fatty acid receptor 1 (GPR40)

Abstract

Six derivatives of 3-phenylpropionic acid bearing various natural and natural-like, spatially defined peripheral motifs have been synthesized and evaluated in vitro for free fatty acid receptor 1 (FFA1) activation. Two frontrunner compounds (bearing a bornyl and cytosine groups) were evaluated in an oral glucose tolerance test in mice where both demonstrated the ability to sustain blood glucose levels following a glucose challenge. The bornyl compound displayed a somewhat superior, dose-dependent efficacy and, therefore, can be regarded as a lead compounds for further development as a therapeutic agent for type 2 diabetes mellitus. Its high affinity to FFA1 was rationalized by docking experiments.

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Preparation of Multi‐Spin Systems: A Case Study of Tolane‐Bridged Verdazyl‐Based Hetero‐Diradicals

Darya E. Votkina, Pavel V. Petunin, Svetlana I. Zhivetyeva, Irina Yu. Bagryanskaya, Mikhail N. Uvarov, Maxim S. Kazantsev,  Marina E. Trusova,  Evgeny V. Tretyakov,  Pavel S. Postnikov

European Journal of Organic Chemistry, Volume 2020, Issue13, April 7, 2020 Pages 1996-2004

Dear Prof. Bagryanskaya,
I am writing on behalf of the Editorial Board to thank and congratulate you for your recent contribution to PCCP, Photochemistry of Tris(2,3,5,6-tetrathiaaryl)methyl Radicals in Various Solutions, DOI: 10.1039/C9CP06213K.
I am delighted to let you know that this was extremely well received, and has been selected by our Editors as a 2019 HOT PCCP article. Please find the collection, now including your publication, here .
As part of the 2019 HOT articles collection, your article will shortly be made free to access until the end of June 2020, and announced to the PCCP community.
Thank you once again for your excellent contribution, and we look forward to receiving your next submission to PCCP.

Kathryn Gempf M. Sci. MRSC
Development Editor,
Journals Royal Society of Chemistry

В журнале Physical Chemistry Chemical Physics, Vol. 22, Iss. 3, 1019-1026, 2020  (IF 3,567) опубликована статья с участием сотрудников Института:   А.А. Кужелева, В.М. Тормышева,  О.Ю. Рогожниковой, М.В. Еделевой и Е.Г. Багрянской

Photochemistry of tris(2,3,5,6-tetrathiaaryl)methyl radicals in various solutions

Abstract

During the last decades, persistent tris(2,3,5,6-tetrathiaaryl)methyl radicals (TAMs) have attracted much attention due to their applications in oximetry, EPR tomography, and as spin labels in pulsed dipolar EPR spectroscopy. Recently, researchers proposed to use TAM radicals as spin labels and/or a partner for photoinduced spin labels. Thus, the questions of their photochemical stability and mechanism of degradation under UV irradiation have become relevant and important. In this study, steady-state photolysis and flash photolysis of TAM radicals were investigated. A detailed mechanism of TAM phototransformations was proposed and confirmed by NMR, gel permeation chromatography, and mass-spectrometric analyses of the products.

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В журнале Dalton Transactions (IF 4,052) опубликована статья с участием сотрудников Института   д.х.н. И.И. Олейника (внс, ЛЭИСМ ) и к.х.н. И.В. Олейник (снс, ЛЭАСМ):

High molecular weight polyethylenes of narrow dispersity promoted using bis(arylimino)cyclohepta[b]pyridine-cobalt catalysts ortho-substituted with benzhydryl & cycloalkyl groups

Abstract

A one-pot template strategy has been utilized to synthesize sterically enhanced bis(imino)cyclohepta[b]pyridine-cobalt(II) chlorides, [2-{(Ar)NCMe}-9-{N(Ar)}C₁₀H₁₀N]CoCl₂ (Ar = 2-(C₅H₉) -4,6-(CHPh₂)₂C₆H₂ Co1, 2-(C₆H₁₁)-4,6-(CHPh₂)₂C₆H₂  Co2, 2-(C₈H₁₅)-4,6-(CHPh₂) ₂C₆H₂ Co3, 2-(C₁₂H₂₃)-4,6-(CHPh₂ )₂C₆H₂ Co4, 2,6-(C₅H₉)₂ -4-(CHPh₂)C₆H₂ Co5). All five complexes have been characterized by a combination of FT-IR spectroscopy, elemental analysis and single crystal X-ray diffraction. The molecular structures of Co1, Co3 and Co5 highlight the substantial steric hindrance imparted by the 2-cycloalkyl-6-benzhydryl or 2,6-dicyclopentyl ortho-substitution pattern; distorted square pyramidal geometries are exhibited in each case. On activation with methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the complexes (apart from Co4/MAO) were active ethylene polymerization catalysts (up to 3.70 ? 10⁶ g PE per mol (Co) per h for Co5/MMAO), operating effectively at temperatures between 50 °C and 60 °C, producing polyethylenes with high molecular weights (up to 589.5 kg mol^-1 for Co3/MAO). Furthermore, all polymers were highly linear (T_m > 130 °C) with narrow dispersities (M_w/M_n range: 2.0–3.0). The coexistence of two chain termination pathways, β-H elimination and transfer to aluminum, has been demonstrated using ¹³ C/¹H NMR spectroscopy.

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В журнале Polymer Chemistry (IF 4,760) опубликована статья с участием сотрудников Института   Д.С. Одинцова (мнс ЛЭАСМ) , к.х.н. И.К. Шундриной (с.н.с. ЛЭАСМ), к.х.н. И.А. Оськиной (с.н.с. ЛГетС), к.х.н. И.В. Олейник (с.н.с. ЛЭАСМ)  и д.х.н. Л.А. Шундрина (зав.лаб. ЛЭАСМ):

Ambipolar polyimides with pendant groups based on 9H-thioxanthene-9-one derivatives: synthesis, thermostability, electrochemical and electrochromic properties

Abstract

New electro-active polyimides (PI) with pendant groups based on 9H-thioxanthene-9-one (Th(O)S) and its S,S-dioxide derivative (Th(O)SO₂) have been synthesized on the basis of 2-{bis(4-aminophenyl)aminomethyl}-9H-Th(O)S/Th(O)SO₂ by the route including the synthesis of the corresponding polyamidoacids followed by their chemical imidization. The synthesized polyimides demonstrated thermal stability up to 400 °C without a noticeable weight loss. Thin-layer cyclic voltammetry showed the polyimides to be capable of reversible electron transfer at low negative potentials, their values depending on the nature of the pendant groups. The electrochromic behavior of the polyimides showed absorption bands at 363, 409, 683 nm for the PI with the Th(O)S pendant group and 355, 644 nm for the PI with the Th(O)SO₂ in the potential sweep range 0 > E > −2.1 V. Optical absorption bands under electrochemical reduction conditions are associated with the formation of radical anion states of the pendant groups inside the PI layer as well as reversible electron transfer to the electron-acceptor moiety of the polymer chain. It was confirmed by comparison with 3D UV-VIS-NIR spectroelectrochemical studies of the corresponding 2-methyl-9H-thioxanthene-9-ones used as precursors of the pendant groups.

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На сайте журнала ACS Applied Materials & Interfaces   (IF=8,456) опубликована статья  с участием сотрудника Института к.х.н. М.С. Казанцева

Fluorinated thiophene-phenylene co-oligomers for optoelectronic devices

ACS Appl. Mater. Interfaces, 2020, 12, 8,  9507-9519
Publication Date:February 3, 2020

Abstract

Organic optoelectronics requires materials combining bright luminescence and efficient ambipolar charge transport. Thiophene-phenylene co-oligomers (TPCOs) are promising highly emissive materials with decent charge-carrier mobility; however, they typically show poor electron injection in devices, which is usually assigned to high energies of their lowest unoccupied molecular orbitals (LUMOs). A widely used approach to lower the frontier orbitals energy levels of a conjugated molecule is its fluorination. In this study, we synthesized three new fluorinated derivatives of one of the most popular TPCOs, 2,2'-(1,4-phenylene)bis[5-phenylthiophene] (PTPTP), and studied them by cyclic voltammetry, absorption, photoluminescence and Raman spectroscopies. The obtained data reveal a positive effect of fluorination on the optoelectronic properties of PTPTP: LUMO levels are finely tuned, photoluminescence quantum yield and absorbance are increased. We then grew crystals from fluorinated PTPTPs, resolved their structures, and showed that fluorination dramatically affects the packing motif and facilitates π-stacking. Finally, we fabricated thin-film organic field-effect transistors (OFETs) and demonstrated a strong impact of fluorination on charge injection/transport for both types of charge carriers, electrons and holes. Specifically, balanced ambipolar charge transport and electroluminescence were observed only in the OFET active channel based on the partially fluorinated PTPTP. The obtained results can be extended to other families of conjugated oligomers and highlight the efficiency of fluorination for rational design of organic semiconductors for optoelectronic devices.

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В журнале Polymer   (IF=8,456) опубликована статья  с участием сотрудника Института д.х.н. Е.Е. Шульц

Pyrocatechol borates: Synthesis, reaction with formaldehyde, and solvent effect on polycondensation process

Polymer

Abstract

Pyrocatechol (I) and dipyrocatechol (II) borates were synthesized by esterification between pyrocatechol (1,2-dihydroxybenzene) and boric acid in о-xylene with azeotropic distillation of water. The co-esterification between pyrocatechol and boric acid with added equimolar quantities of phenol or 2,6-di-tert-butylphenol was studied, and pyrocatechol phenyl (III) and pyrocatechol-(2,6-di-tert-butyl)phenyl (IV) borates were prepared. The reaction of the resultant esters with formaldehyde in the presence of boron trifluoride etherate as a catalyst was examined. The coupling of the methylene moiety in several position of moleculeIII was found to be dependent on the solvent used. The electrophilic substitution on the phenol substituent took place in о-xylene, while the reaction in either benzene or molten monomer proceeded to substitute the methylene moiety for the proton on the catechol moiety. The molecular weights of the compounds were measured. Some properties of the synthesized oligomers were determined and thermal and thermooxidative destruction was examined.

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В журнале New Journal of Chemistry, 2019, Vol. 43, N 41, Pp. 16331-16-337,  (IF 3,069) опубликована статья с участием сотрудников Института:   к.х.н. Н.А. Семёнова, Е.А. Радюш, Е.А. Чулановой, д.х.н. И.Ю. Багрянской, к.х.н. Иртеговой, д.х.н. Л.А. Шундрина и д.х.н. А.В. Зибарева

Design, synthesis and isolation of a new 1,2,5-selenadiazolidyl and structural and magnetic characterization of its alkali-metal salts

Abstract

5,6-Dicyano[1,2,5]selenadiazolo[3,4-b]pyrazine 1 was synthesized and electrochemically and chemically reduced into its radical anion [1]˙−, which was characterized by EPR spectroscopy and DFT calculations, and isolated in the form of homospin salts [K(18-crown-6)]+[1]˙− (2) and [Na(18-crown-6)]+[1]˙− (3). The crystal structure of 2 revealed π-dimers of [1]˙− featuring a shortened interplanar separation of 3.18 Å, and that of 3 showed chains of alternating cations and anions. DFT and CASSCF calculations on the π-dimers of [1]˙− suggest a closed-shell singlet ground state with a noticeable contribution of diradical character. According to EPR and SQUID magnetometry, salt 2 is diamagnetic in the range of 2–300 K, whereas salt 3 is paramagnetic and reveals weak antiferromagnetic exchange interactions.

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