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11.
Temiloluwa T. Adejumo Marianna Danopoulou Leandros P. Zorba Dr. Andrej Pevec Dr. Matija Zlatar Dr. Dušanka Radanović Milica Savić Prof. Dr. Maja Gruden Prof. Dr. Katarina K. Anđelković Prof. Dr. Iztok Turel Dr. Božidar Čobeljić Prof. Dr. Georgios C. Vougioukalakis 《欧洲无机化学杂志》2023,26(33):e202300193
Two new Zn(II) complexes bearing tridentate hydrazone-based ligands with NNO or NNS donor atoms were synthesised and characterised by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies, and single crystal X-ray diffraction methods. These complexes, together with four previously synthesised analogues, having hydrazone ligands with a NNO donor set of atoms, were successfully employed as catalysts in the ketone-amine-alkyne (KA2) coupling reaction, furnishing tetrasubstituted propargylamines, compounds with unique applications in organic chemistry. DFT calculations at the CAM-B3LYP/TZP level of theory were performed to elucidate the electronic structure of the investigated Zn(II) complexes, excellently correlating the structure of the complexes to their catalytic reactivity. 相似文献
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A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the corresponding 6-methyl-3-aryl imidazo[1,2-b]isoxazoles 3 in good yields.Compounds 3 on treatment with 37% formaline and secondary amines furnished the corresponding novel Mannich bases viz., 6-methyl-3-aryl-2-(morpholine/pyrrolidin-1-yl/piperidin-1-yl)-methyl-imidazo[1,2-b]isoxazoles 4–6. 相似文献
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Dynamic Covalent Organocatalysts Discovered from Catalytic Systems through Rapid Deconvolution Screening 下载免费PDF全文
Fredrik Schaufelberger Prof. Olof Ramström 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(36):12735-12740
The first example of a bifunctional organocatalyst assembled through dynamic covalent chemistry (DCC) is described. The catalyst is based on reversible imine chemistry and can catalyze the Morita–Baylis–Hillman (MBH) reaction of enones with aldehydes or N‐tosyl imines. Furthermore, these dynamic catalysts were shown to be optimizable through a systemic screening approach, in which large mixtures of catalyst structures were generated, and the optimal catalyst could be directly identified by using dynamic deconvolution. This strategy allowed one‐pot synthesis and in situ evaluation of several potential catalysts without the need to separate, characterize, and purify each individual structure. The systems were furthermore shown to catalyze and re‐equilibrate their own formation through a previously unknown thiourea‐catalyzed transimination process. 相似文献
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Dr. Aleksandrs Prokofjevs 《Angewandte Chemie (International ed. in English)》2015,54(45):13401-13405
Thermally induced dehydrogenation of the H‐bridged cation L2B2H5+ (L=Lewis base) is proposed to be the key step in the intramolecular C? H borylation of tertiary amine boranes activated with catalytic amounts of strong “hydridophiles”. Loss of H2 from L2B2H5+ generates the highly reactive cation L2B2H3+, which in its sp2‐sp3 diborane(4) form then undergoes either an intramolecular C? H insertion with B? B bond cleavage, or captures BH3 to produce L2B3H6+. The effect of the counterion stability on the outcome of the reaction is illustrated by formation of LBH2C6F5 complexes through disproportionation of L2B2H5+ HB(C6F5)3?. 相似文献
15.
Different Types of Nickel,Cobalt, and Manganese Complexes originating from 2‐Imidazolecarboxaldiimine of Triethylenetetraamine 下载免费PDF全文
The reactivity of the 2‐imidazolecarboxaldiimine of triethylenetetraamine (H2imida) towards divalent manganese, cobalt, and nickel ions differs. It forms a cationic nickel(II) complex by acting as a hexa‐dentate ligand, whereas the cobalt(II) complex formation took place by deprotonation of the H2imida forming a neutral complex with imida. Deprotonation of the ligand by H2imida by cobalt(II) ions caused quenching of the fluorescence emission at 312 nm, such a quenching effect was not observed with the nickel ions. On the other hand, a mononuclear manganese(II) complex of a new tetradentate ligand was formed by manganese(II) assisted intramolecular cyclization reactions of H2imida. 相似文献
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In this article, we present a Python‐based library of high quality semi‐global potential energy surfaces for 50 polyatomic molecules with up to six atoms. We anticipate that these surfaces will find widespread application in the testing of new potential energy surface construction algorithms and nuclear ro‐vibrational structure theories. To this end, we provide the ability to generate the energy derivatives required for Taylor series expansions to sixth order about any point on the potential energy surface in a range of common coordinate systems, including curvilinear internal, Cartesian, and normal mode coordinates. The PyPES package, along with FORTRAN, C, MATLAB and Mathematica wrappers, is available at http://sourceforge.net/projects/pypes-lib . © 2015 Wiley Periodicals, Inc. 相似文献
17.
以食品发热包为主题情境,通过探析发热包成分、解密发热原理、计算原料配比、配制发热包等环节梳理酸和碱的性质、用途。从元素观、转化观的视角认识物质转化规律,体现物质研究的一般思路,凸显科学探究的基本过程。通过设计方案测定发热包中碳酸钠的含量,总结混合物成分鉴定及定量测定的方法;归纳气体定量测定的影响因素。呈现一堂学科观念、学科方法教学具体课例,凸显物质研究、定性检验、定量测定的基本方法。 相似文献
18.
以北京师范大学化学专业的无机化学课程改革为例,从教学内容、教学方法、课程考核等方面探讨无机化学课程优化和改革。明确教学目标,提升教学质量,达成化学(师范)专业的毕业要求,全面提升学生的思想政治素养、专业知识技能和教育情怀。 相似文献
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