• Kögel J.F., Timoshkin A.Y., Schröder A., Lork E., Beckmann J., Al(OCArF3)3 - A Thermally Stable Lewis Superacid Chem. Science, 2018, doi 10.1039/c8sc02981d, IF = 9.1

    The adduct free Lewis superacid Al(OCArF3)3 was obtained by the reaction of ArF3COH with AlEt3 and fully characterized (ArF = C6F5). It comprises a high thermal stability up to 180 °C and a distinct reactivity towards Lewis bases, as exemplified by the isolation of the neutral adducts Al(OCArF3)·D (D = MeCN, THF, Et2O, pyridine, OPEt3), the fluoride complexes [Q][FAl(OCArF)3] (Q+ = Cs+, Ag+, Tl+, [S(NMe2)3]+, [Ph3C]+, Li+, [NBu4]+, [FeCp2]+) and the chloride complex [Ph3C][ClAl(OCArF)3].

  • Agafonova A.V., Smetanin I.A., Rostovskii N.V., Khlebnikov A.F., Novikov M.S. Expedient synthesis of 3-hydroxypyrroles via Bu3SnH-triggered ionic 5-exo-trig-cyclization of 5-chloro-3-azamuconoate derivatives Org. Chem. Front. 2018, doi 10.1039/c8qo00982a, IF=5.455

    An unprecedented application of tributyltin hydride (TBTH) as a reagent for the reductive ionic 1,5-cyclization of 3-azamuconoates (3-azahexa-2,4-dienedioates) is described. A novel 1,5-exo-trig-cyclization of 5-chloro-3-azamuconoates was used as a base for the development of an effective two-step method for the preparation of 4-hydroxy-1H-pyrrole-3-carboxylic and 3-hydroxy-1H-pyrrole-2,4-dicarboxylic acids derivatives from readily available diazo esters and 2-chloro-2H-azirines or 4-chloroisoxazoles. The experimental results, as well as the DFT calculations of the pyrroles formation, are in good agreement with the ionic mechanism involving the initial hydride attack at the CN bond of the azamuconoate followed by tin-promoted 1,5-cyclization.

  • Anastasia I. Solomatina, Pavel S. Chelushkin, Tatiana O. Abakumova, Vladimir A. Zhemkov, Mee-Whi Kim, Ilya Bezprozvanny, Vladislav V. Gurzhiy, Alexey S. Melnikov, Yuri A. Anufrikov, Igor O. Koshevoy, Shih-Hao Su, Pi-Tai Chou, Sergey P. Tunik Reactions of Cyclometalated Platinum(II) [Pt(N^C)(PR3)Cl] Complexes with Imidazole and Imidazole-Conjugated Biomolecules: Fine-Tuning Reactivity and Photophysical Properties via Ligand Design, Inorg. Chem., 2018. Article in Press. DOI: 10.1021/acs.inorgchem.8b02204 IF=4.7

    Chemical and structural aspects of the [Pt(NC)PR3Cl] complexes conjugation with ubiquitin and albumin were investigated in detail. Rapid, selective, and quantitative coordination of the platinum complex to imidazole function of the proteins enabled their regioselective labeling and also paves the way to application of the conjugates in quantitative mapping of oxygen concentration in cells using PLIM microscopy.

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Репрезентативные публикации за июнь 2018 г.

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I.O. Koshevoy, V. Sivchik, Rajib Sarker, Zong-Ying Liu, Kun-You Chung, E.V. Grachova, A.J. Karttunen, and Pi-Tai Chou, Improvement of the photophysical performance of platinum cyclometalated complexes in halogen bonded adducts, Chem. Eur. J., 2018, 24, 11475–11484, doi: 10.1002/chem.201802182

Три группы люминесцирующих платиновых комплексов [Pt(C^N)(L)(Y)] были исследованы как акцепторы галогенной связи в отношении иодфторбензолов (IC6F5 и I2C6F4). Производные фосфиноцианида (L/Y = PPh3/CN) кристаллизуются совместно как с IC6F5, так и с I2C6F4. В то время как нативные комплексы являются довольно плохими люминофорами в твердом состоянии (Φ = 0,02-0,09), аддукты проявляют до 10-кратного увеличения интенсивности свечения с незначительным изменением энергии эмиссии. Наблюдаемое усиление квантовой эффективности объясняется главным образом совместным влиянием нековалентных взаимодействий, которые регулируют режим кристаллической упаковки.

Abstract

Three groups of luminescent platinum complexes [Pt(C^N)(L)(Y)] [C^N=benzothienyl‐pyridine (1), bezofuryl‐pyridine (2), phenyl‐pyridine (3); L/Y=DMSO/Cl (a), PPh3/Cl (b), PPh3/CN (c)] have been probed as halogen‐bond (XB) acceptors towards iodofluorobenzenes (IC6F5 and I2C6F4). Compounds 1 a and 2 a (L/Y=DMSO/Cl) afford the adducts 1 a⋅⋅⋅I2C6F4 and 2 a⋅⋅⋅I2C6F4, which feature I⋅⋅⋅Sbtpy/I⋅⋅⋅πbtpy and I⋅⋅⋅ODMSO/I⋅⋅⋅Cl short contacts, respectively. The phosphane‐cyanide derivatives 1 c and 2 c (L/Y=PPh3/CN) co‐crystallise with both IC6F5 and I2C6F4. None of the phpy‐based species 3 a3 c participated in XB interactions. Although the native complexes are rather poor luminophores in the solid state (Φem=0.023–0.089), the adducts exhibit an up to 10‐fold increase of the intensity with a minor alteration of the emission energy. The observed gain in the quantum efficiency is mainly attributed to the joint influence of non‐covalent interactions (halogen/hydrogen bonding, π–π stacking), which govern the crystal‐packing mode and diminish the radiationless pathways for the T1→S0 transition by providing a rigid environment around the chromophore.


Koronatov A.N., Rostovskii N.V., Khlebnikov A.F., Novikov M.S. Rh(II)-Catalyzed Ring Expansion of Pyrazoles with Diazocarbonyl Compounds as a Method for the Preparation of 1,2-Dihydropyrimidines, J. Org. Chem., 2018, doi: 10.1021/acs.joc.8b01228

В работе описана новая Rh(II)-катализируемая реакция диазокарбонильных соединений с 1,4-ди- и 1,4,5-тризамещенным пиразолами как первый пример внедрения карбеноида в простую связь N-N. Эта новая реакция представляет собой новый подход к 4-незамещенным 1,2-дигидропиримидинам, позволяющий осуществлять широкое варьирование функциональных групп в целевом гетероцикле. Согласно DFT расчетам, расширение пиразольного цикла протекает через последовательное образование связанного с металлом пиразолиевого илидая, свободного пиразолиевого илида и 1,5-диазагексатриена,претерпевающего 1,6-циклизацию на последней стадии домино процесса.

Abstract

A high yield synthesis of 1,2-dihydropyrimidines by the Rh(II)-catalyzed reaction of diazocarbonyl compounds with 1,4-di- and 1,4,5-trisubstituted pyrazoles is reported. This reaction represents the first example of a carbenoid insertion into a N–N bond and provides a novel approach to 4-unsubstituted 1,2-dihydropyrimidines with a broad range of functional group tolerance. According to DFT calculations, the pyrazole ring expansion proceeds via the sequential formation of the metal-bound pyrazolium ylide, metal-free pyrazolium ylide, and 1,5-diazahexatriene followed by 1,6-cyclization.).


Maria P. Sokolova, Michael A. Smirnov, Artemiy A. Samarov, Natalya V. Bobrova, Vitaly K. Vorobiov, Elena N. Popova, Elizaveta Filippova, Pavel Geydt, Erkki Lahderanta, Alexander M. Toikka Plasticizing of chitosan films with deep eutectic mixture of malonic acid and choline chloride, Carbohydrate Polymers, V. 197, 548–557, 2018, doi: 10.1016/j.carbpol.2018.06.037

Получены и исследованы пленки хитозана, содержащие глубокий эвтектический растворитель (DES) на основе малоновой кислоты и хлориде холина. Содержание DES варьировалось от 0 до 82 вес%. Анализ изотерм сорбции воды, данные атомно-силовой микроскопии и результаты Фурье ИК-спектроскопии подтвердили сильное взаимодействие хитозана с компонентами ДЭС. Пластифицирующий эффект DES отражают проведенные статические объемные механические измерения, термический анализ и количественное наномеханическое картирование (QNM). Введение DES в пленки хитозана приводит к температуре стеклования в области +2 - 2.3 °C. Результаты QNM подтверждают однородность пленок, содержащих до 75 мас.% DES.

Abstract

Chitosan (CS) films containing deep eutectic solvent (DES) based on malonic acid (MA) and choline chloride (ChCl) were successfully prepared by solution casting method by using DES content ranging from 0 to 82 wt%. A strong interaction of CS with the components of DES was demonstrated by analyses of water sorption isotherms, atomic force microscopy and FTIR results. The plasticizing effect of the MA and ChCl mixture on the CS matrix was shown by static bulk mechanical measurements, thermal analysis and quantitative nanomechanical mapping (QNM). Elongation at break increased from 3 to 62% at increase of DES content from 0 to 67 wt%, while further increase of DES content led to the decreasing of maximal elongation. Introduction of DES into CS films led to the appearance of glass transition temperature in the region +2 - -2.3 °C. QNM results indicated homogeneity of the films containing up to 75 wt% of DES.

Ответственный за содержание сайта Института химии: Роман Зумберов, r.zumberov@spbu.ru