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21.
Oleg G. Salnikov Kirill V. Kovtunov Danila A. Barskiy Valery I. Bukhtiyarov Robert Kaptein Igor V. Koptyug 《Applied magnetic resonance》2013,44(1-2):279-288
Parahydrogen-induced polarization has been successfully used for a kinetic study of propylene hydrogenation over a Pt/Al2O3 catalyst. It was shown that the reaction orders with respect to hydrogen are different for the pairwise and the non-pairwise hydrogen addition and are equal to 0.7 and 0.1, respectively. This observation of different reaction orders confirms the coexistence of different types of active sites which are responsible for the overall and the pairwise hydrogen addition to the propylene C=C double bond. Moreover, 0.7 reaction order with respect to H2 for pairwise hydrogen addition indicates that the contribution of pairwise addition depends on the concentration of molecular hydrogen. Therefore, this observation can be developed into a practical tool for producing fluids with highly polarized nuclear spins by changing the hydrogen concentration. 相似文献
22.
A simple and convenient methodology for the synthesis of N,N′-disubstituted ureas from primary amines by a heterogenized catalyst montmorillonitebipyridinepalladium (II)acetate for the first time at room temperature and atmospheric pressure is described. 相似文献
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Vereshchagin Anatoly N. Karpenko Kirill A. Elinson Michail N. Goloveshkin Alexander S. Ushakov Ivan E. Egorov Mikhail P. 《Research on Chemical Intermediates》2018,44(9):5623-5634
Research on Chemical Intermediates - A novel four-component stereoselective synthesis of polysubstituted piperidines is reported. The Knoevenagel–Michael–Mannich cascade of two... 相似文献
27.
Kirill Kulish Cosimo Boldrini Dr. Marta Castiñeira Reis Dr. Juana M. Pérez Prof. Dr. Syuzanna R. Harutyunyan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15843-15846
Two-step dearomative functionalization of naphthols promoted by Lewis acids and copper(I) catalysis was developed. Initially, Lewis acid complexation inverted the electronic properties of the ring and established an equilibrium with the dearomatized counterpart. Subsequent trapping of the dearomatized intermediate with organometallics as well as organophosphines was demonstrated and provided the corresponding dearomatized products. 相似文献
28.
Back Cover: Single‐Atom Gold Catalysis in the Context of Developments in Parahydrogen‐Induced Polarization (Chem. Eur. J. 19/2015)
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29.
Kirill V. Zaitsev Yulia A. Piskun Yuri F. Oprunenko Sergey S. Karlov Galina S. Zaitseva Irina V. Vasilenko Andrei V. Churakov Sergei V. Kostjuk 《Journal of polymer science. Part A, Polymer chemistry》2014,52(9):1237-1250
The aluminum complexes containing two iminophenolate ligands of the type (p‐XC6H4NCHC6H4O‐o)2AlR' (R′=Me ( 3, 4 ) or R′=O(CH2)4OCH=CH2 ( 5, 6 ), X=H ( 3, 5 ), F( 4, 6 )) were synthesized and characterized by 1H, 13C NMR spectroscopy, and X‐ray crystallography. The reaction of AlMe3 with two equivalents of substituted iminophenols gave five‐coordinated {ONR}2AlMe ( 3, 4 ) complexes. Subsequent reaction of these methyl complexes with unsaturated alcohol, HO(CH2)4OCH=CH2, resulted in target compounds 5 and 6 in a good yield. It was shown that the complexes ( 3 ‐ 6 ) are monomeric in solution (NMR) and in solid state (X‐ray analysis). The catalytic activity of the complexes 5 and 6 towards ring‐opening polymerization (ROP) of ?‐caprolactone and d,l ‐lactide was assessed. Complex 5 showed higher activity as compared with 6 , while both of these catalysts induced controlled homo‐ and copolymerization to afford the macromonomers with high content of vinyl ether end groups (Fn > 80%) in a broad range of molecular weights (Mn = 4000–30,000 g mol?1) with relatively narrow MWD (Mw/Mn = 1.1–1.5). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1237–1250 相似文献
30.
Insun Park Kirill Efimenko Johan Sjöblom 《Journal of Dispersion Science and Technology》2013,34(3):318-327
We have developed a simple, robust, and efficient technology utilizing cheap and recoverable materials based on commercially available silicone elastomer networks for removing organic solvents and crude oil from waters. Hydrophobic and oleophilic properties of silicone elastomers endow poly(dimethyl siloxane) (PDMS) with the capacity to absorb a large variety of organics, including benzene (B), toluene (T), ethylbenzene (E), and xylene (X), commonly referred to as BTEX, and also crude oils, while at the same time enabling the organic “sponges” to float on waters, which facilitates straightforward handling. We developed a method for generating PDMS particles with variable sizes (ranging from hundreds nanometers to few millimeters) by drop-wise depositing siloxane/cross-linker mixtures into warm water, a process which leads to the cross-linking of the PDMS components. We have tested the capability of the PDMS particles to remove toluene and benzene from water. We also performed similar experiments by utilizing PDMS sheets. In both instances we observed a rapid sorption of the organic phase into PDMS; the amount of absorbed organic solvent depended on the concentration in water and the total mass (volume) of PDMS and did not depend on the geometry of the PDMS “sponge.” In addition, we have examined the uptake of toluene and benzene from toluene/benzene (T/B) mixtures dissolved in water. Our results indicate that the amount of benzene absorbed from the T/B mixtures into PDMS increases relative to the uptake from pure benzene/water solutions. This behavior is associated with toluene acting as a “surfactant” that effectively replaces the more unfavorable PDMS/B contacts with less costly T/B ones. Finally, a simple experiment demonstrates qualitatively that PDMS is also capable of removing crude oils from oil-contaminated waters. 相似文献