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A highly effective, economical, and environmentally friendly method using of CAN as oxidant and water as solvent for oxidative coupling of N,N-dialkylarylamines was reported. 相似文献
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An iodine-catalyzed aerobic-oxidative C-H functionalization of o-alkylazoarenes to afford 2H-indazoles has been developed. CuI was found to be an effective additive to accelerate the regeneration of iodine in the catalytic cycle. This catalytic system is suitable for both electron-rich and electron-deficient azoarenes and tolerates a variety of functional groups with high yields. A gram-scale reaction was successfully conducted, proving the scalability of this reaction. 相似文献
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以4,6-二烷氧基-1,3-苯二磺酰氯和芳香二酚为原料,三乙胺作缚酸剂,二氯甲烷作溶剂,采取一步成环法合成了3种磺酸酯桥联大环化合物。合成产物的结构用IR、1H NMR、13C NMR和MALDI-TOF等技术手段进行了确认。利用紫外光谱分析的方法研究了4,6,16,18-四正戊氧基-11,23-二甲基-1,3,13,15-四磺酸酯间苯芳香大环(5)对Ca2+、Pb2+及部分过渡金属等20种金属离子的识别。结果发现,其对Sn2+显示出一定的选择性,由于Sn2+和Bi3+协同作用的影响,在化合物5-Sn2+的体系中加入Bi3+,紫外吸收光谱在325 nm左右的吸收增强了许多,这说明化合物5对Bi3+显示出优于Sn2+的较好选择性。 相似文献
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1,4-Dilithio-1,3-dienes or zirconacyclopentadienes reacted with oxalyl chloride in the presence of CuCl in a 1,1-cycloaddition manner to give cyclopentadienone derivatives in high yields along with the elimination of CO. 相似文献
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Efficient synthetic approaches to higher para-dihydroquinones and -quinones have been developed through zirconium/CuCl-mediated cycloaddition reactions of two alkynes and quinone in a one-pot procedure. 相似文献
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Chanjuan Zhang Dr. Philipp Gotico Dr. Regis Guillot Dr. Diana Dragoe Dr. Winfried Leibl Dr. Zakaria Halime Prof. Ally Aukauloo 《Angewandte Chemie (International ed. in English)》2023,62(8):e202300926
At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate the interconversion between CO2 and CO. We have designed a molecular catalyst implementing a bimetallic iron complex with an embarked second coordination sphere with multi-point hydrogen-bonding interactions. We found that, when immobilized on carbon paper electrode, the dinuclear catalyst enhances up to four fold the heterogeneous CO2 reduction to CO in water with an improved selectivity and stability compared to the mononuclear analogue. Interestingly, quasi-identical catalytic performances are obtained when one of the two iron centers was replaced by a redox inactive Zn metal, questioning the cooperative action of the two metals. Snapshots of X-ray structures indicate that the two metalloporphyrin units tethered by a urea group is a good compromise between rigidity and flexibility to accommodate CO2 capture, activation, and reduction. 相似文献
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(6aR,11aR)-4,9-dimethoxy-3-hydroxypterocarpan was isolated from the natural plant of Caragana spinifera Kom (Leguminosae). The structure was elucidated by infrared spectra(IR), mass spectrometry(MS), 1H-Nuclear magnetic resonance(1H-NMR),13C-Nuclear Magnetic Resonance(13C-NMR), 1H-1H correlation spectroscopy(1H-1H COSY), heteronuclear multiple quantum coherence(HMQC) and heteronuclear multiple bond coherence(HMBC). In addition, its crystal structure was determined by the single-crystal X-ray diffraction analysis. It crystalized in monoclinic, space group P21 with a=6.4778(13), b=12.631(3), c=8.8368(18)(A), β= 95.8(3)o, C17H16O5, Mr=300.30, V=719.3(3)(A)3, Z=2, Dc=1.386 Mg/m3, F(000)=316, μ=0.102 mm-1, the final R=0.0332 and wR=0.0862 for 1533 observed reflections (I>2σ(I)). The molecular backone of the compound includes a benzofuro and a benzopyran. The X-ray analysis shows that the absolute configuration of the compound is cis-pterocarpan. 相似文献
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In this paper, we investigate a multi-period portfolio optimization problem for asset–liability management of an investor who intends to control the probability of bankruptcy before reaching the end of an investment horizon. We formulate the problem as a generalized mean–variance model that incorporates bankrupt control over intermediate periods. Based on the Lagrangian multiplier method, the embedding technique, the dynamic programming approach and the Lagrangian duality theory, we propose a method to solve the model. A numerical example is given to demonstrate our method and show the impact of bankrupt control and market parameters on the optimal portfolio strategy. 相似文献
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Chunbo Lai Chanjuan Xi Yuping Feng 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):449-455
Alkyllithium reacts with chlorophosphate to generate the α -lithio- alkylidenediphosphonate, which further reacts with halogen reagents to afford corresponding α -halogenated alkylidenediphosphonates. 相似文献