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71.
Andrey A. Mikhaylov Alexander D. Dilman Roman A. Kunetsky Marina I. Struchkova Sema L. Ioffe Vladimir A. Tartakovsky 《Tetrahedron letters》2010,51(7):1038-4594
A series of 3-halomethyl-5,6-dihydro-1,2-oxazine N-oxides (halogen = Cl, Br, I) is prepared from 4-phenyl-3,6,6-trimethyl-5,6-dihydro-4H-oxazine N-oxide by means of a silylation/halogenation sequence. The obtained halogenated N-oxides undergo reactions typical of cyclic six-membered nitronates including 1,3-dipolar cycloaddition, addition of nucleophiles, and substitution of the halogen by C-, S-, and N-nucleophiles. 相似文献
72.
Investigation of the effect of the α-CH3-group on low-temperature postpolymerization in devitrifying matrices leads to the following conclusions. 1. The low-temperature postpolymerization in supercooled alcohol solutions (Tg ~ 102 K) is quite efficient with acrylic monomers. Inactivity of their methacrylic analogues under these conditions is attributed to steric screening of the unpaired electron in the growing radicals. 2. As the temperature is raised and the CH3-group vibration intensity increases, the screening effect fades. Thus in devitrifying water-alcohol solutions of NaAA and NaMAA, at higher temperatures the postpolymerization is efficient in both cases. Data on copolymerization of NaAA and NaMAA indicate that at ~ 170 K the steric limitations due to the CH3-group are eliminated. 3. In a glycerine matrix (), all the acrylic and methacrylic monomers studied show efficient polymerization over virtually the same temperature range. It is concluded that the a-CH3-group in methacrylic monomers appreciably affects their polymerization activity only at low temperatures, where steric screening of the growing polymer radical becomes important. 相似文献
73.
In this paper we consider the rotational transitions induced by centrifugal distortion in polar or quasipolar symmetric top molecules belonging to the point groups Cn and Cnv (n ≥ 3). It is shown that in this series only the molecules of point groups C3, C3v, C4, and C4v may possess rotational spectra induced by first-order centrifugal distortion. A general expression is given for the effective dipole moment operator and for its matrix elements. The peak absorption coefficients for some of the strongest ΔK = 3 transitions of the CH3D molecule have been calculated and compared with the peak absorption coefficients of allowed transitions. 相似文献
74.
V. I. Volkov I. N. Meshkov V. A. Mikhaylov G. V. Trubnikov A. V. Tuzikov A. A. Fateev 《Physics of Particles and Nuclei Letters》2014,11(5):675-690
A project of the system of heavy-ion beam injection into the Booster synchrotron of the NICA accelerator complex developed at the Joint Institute for Nuclear Research (Dubna) is considered. The proposed system provides multivariant injection for accumulating beams with required intensity. The main methods of beam injection into the Booster are described. These are the methods of one-turn, multiturn, and multiple injections. The results of beam dynamics simulations are presented. 相似文献
75.
Selective Targeting of Tumor and Stromal Cells By a Nanocarrier System Displaying Lipidated Cathepsin B Inhibitor 下载免费PDF全文
G. Mikhaylov Dr. D. Klimpel Dr. N. Schaschke Dr. U. Mikac M. Vizovisek Dr. M. Fonovic Prof. V. Turk Prof. Boris Turk Dr. Olga Vasiljeva 《Angewandte Chemie (International ed. in English)》2014,53(38):10077-10081
Cathepsin B (CtsB) is a lysosomal cysteine proteinase that is specifically translocated to the extracellular milieu during cancer progression. The development of a lipidated CtsB inhibitor incorporated into the envelope of a liposomal nanocarrier (LNC‐NS‐629) is described. Ex vivo and in vivo studies confirmed selective targeting and internalization of LNC‐NS‐629 by tumor and stromal cells, thus validating CtsB targeting as a highly promising approach to cancer diagnosis and treatment. 相似文献
76.
Mikhaylov D Gryaznova T Dudkina Y Khrizanphorov M Latypov S Kataeva O Vicic DA Sinyashin OG Budnikova Y 《Dalton transactions (Cambridge, England : 2003)》2012,41(1):165-172
Electrocatalytic generation of nickel catalysts in low oxidation states by reduction of nickel complexes with various ligands (2,2'-bipyridine, 2,2':6',2'-terpyridine, (S,S)-2,6-bis(4-phenyl-2-oxazolin-2-yl)-pyridine) in the presence of olefinic substrates and fluoroalkyl halides leads to new organic products derived from addition-dimerization processes. Due to the presence of two stereocenters in the dimerization products two diastereomers were characterized by a variety of analytical techniques including multi-dimensional NMR methods and X-ray single crystal diffraction. The formation of dimers was prevented by the inclusion of the hydrogen atom donor tributyltin hydride. The cyclic voltammetry study of selected nickel complexes along with fluoroalkyl halides demonstrated that Ni(I)L is the active form of the catalyst. 相似文献
77.
Alexander G. Medvedev Alexey A. Mikhaylov Andrei V. Churakov Petr V. Prikhodchenko Ovadia Lev 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(3):i20-i24
Diammonium carbonate hydrogen peroxide monosolvate, 2NH4+·CO32−·H2O2, (I), and dicaesium carbonate hydrogen peroxide trisolvate, 2Cs+·CO32−·3H2O2, (II), were crystallized from 98% hydrogen peroxide. In (I), the carbonate anions and peroxide solvent molecules are arranged on twofold axes. The peroxide molecules act as donors in only two hydrogen bonds with carbonate groups, forming chains along the a and c axes. In the structure of (II), there are three independent Cs+ ions, two of them residing on twofold axes, as are two of the four peroxide molecules, one of which is disordered. Both structures comprise complicated three‐dimensional hydrogen‐bonded networks. 相似文献
78.
Paweł M. Szczepanik Dr. Andrey A. Mikhaylov Dr. Ondřej Hylse Roman Kučera Petra Daďová Dr. Marek Nečas Dr. Lukáš Kubala Dr. Kamil Paruch Dr. Jakub Švenda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(1):e202213183
We report a new synthetic strategy for the flexible preparation of forskolin-like molecules. The approach is different from the previously published works and employs a convergent assembly of the tricyclic labdane-type core from pre-functionalized cyclic building blocks. Stereoselective Michael addition enabled the fragment coupling with excellent control over three newly created contiguous stereocenters, all-carbon quaternary centers included. Silyl enol ether-promoted ring-opening metathesis paired with ring closure were the other key steps enabling concise assembly of the tricyclic core. Late-stage functionalization sequences transformed the tricyclic intermediates into a set of different forskolin-like molecules. The modular nature of the synthetic scheme described herein has the potential to become a general platform for the preparation of analogs of forskolin and other complex tricyclic labdanes. 相似文献