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931.
932.
An efficient one‐pot method for the synthesis of hydroxyflavanones is described. Methoxychalcones are treated with 36% HBr to afford cyclization and regioselective O‐demethylation products (2a–i) while cyclization and complete O‐demethylation products (3a–e) are obtained in the presence of 45% HI. 相似文献
933.
934.
Nonlinear Dynamics - This paper investigates the problem of the stability analysis for fractional-order nonlinear systems. First, we investigate the asymptotic behavior of the system solution by... 相似文献
935.
An efficient synthetic method for the pentasubstituted pyrroles was successfully developed via the one-pot domino reactions of arylamines, acetylenedicarboxylates, and 3-phenacylideneoxindoles. The reaction mechanism involved the sequential Michael addition and ring closure of the in situ generated β-active enamino ester. 相似文献
936.
Prof. Ying Wang Ping Xu Qiong Xie Qing‐Qing Ma Yan‐Hui Meng Dr. Zi‐Wen Wang Dr. Shaowei Zhang Prof. Dr. Xiao‐Jun Zhao Prof. Dr. Jun Chen Prof. Dr. Zhong‐Liang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10459-10474
A bidentate ligand, 1‐{4‐[4‐(1H‐1,2,4‐triazol‐1‐yl)phenoxy]phenyl}‐1H‐1,2,4‐triazole (TPPT), has been designed and synthesized. By using TPPT as a building block for self‐assembly with Cd(NO3)2 ? 4 H2O and CdCl2 ? 10.5 H2O, novel 1D double‐chain {[Cd(TPPT)(NO3)2] ? 3 H2O}n ( 1 ) and 2D (4,4) layer [Cd(TPPT)Cl2(H2O)]n ( 2 ) have been constructed. When 1 was employed as a precursor and exposed to DMF or N,N′‐dimethylacetamide (DMAC), the crystals of 1 dissolved and reassembled into two types of brown block‐shaped crystals of 1D double chains: {[Cd(TPPT)2(NO3)2] ? DMF}n ( 1 a ) and {[Cd(TPPT)2(NO3)2] ? DMAC}n ( 1 b ). The anion‐exchange reactions of complex 2 have also been investigated. After gently stirring crystals of 2 in CHCl3/C2H5OH/H2O containing NaBr, NaI ? 2 H2O, or NaOAc ? 3 H2O, the crystals retained their crystalline appearances. A remarkable single crystal to single crystal transformation was observed and 1D double chains of {[Cd(TPPT)Br2] ? C2H5OH}n ( 2 a ) and {[Cd(TPPT)2I2] ? CHCl3}n ( 2 b ), and 1D single chains of [Cd(TPPT)(H2O)2(CH3COO)2]n ( 2 c ), can be obtained. Luminescent properties indicate that 1 shows excellent selectivity for Ca2+ and cyano complexes. To the best of our knowledge, this is the first example of a luminescent probe for Ca2+ based on triazole derivatives. 相似文献
937.
价廉易得的L-亮氨酸先以苄基同时保护氨基及羧基得(S)-2-(二苄胺基)-4-甲基戊酸苄酯,进而在碱性条件下与乙腈发生亲核取代反应得(S)-4-(二苄胺基)-6-甲基-3-氧代庚腈,再经硼氢化钠选择性还原羰基得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚腈,用双氧水氧化得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚酸,最后在Pd(OH)2/C-H2作用下脱掉苄基得到(3S,4S)-4-氨基-3-羟基-6-甲基庚酸,即(3S,4S)-statine。整个合成路线总产率为33.6%。 相似文献
938.
Chen Yang Ying Chen Dan Liu Jinfeng Wang Cheng Chen Jiemin Wang Ye Fan Shaoming Huang Weiwei Lei 《Frontiers of Physics》2018,13(4):138101
Vertically aligned γ-AlOOH nanosheets (NSs) have been successfully fabricated on flexible Al foils via a solvothermal route without morphology-directing agents. Three different reaction temperature (25, 80, and 120 ?C) and time (30 min, 45 min, and 24 h) are discussed for the growth period, which efficiently tune the density and size of the γ-AlOOH NSs. Meanwhile, the growth speed of the nanosheets confirms that dominant growth stage is seen in the initial 45 min. Furthermore, the interlayer of the γ-AlOOH NSs displays an average height of 140 nm and superhydrophilicity. By dynamic adsorption, the assynthesized γ-AlOOH NSs exhibit an outstanding NH3 adsorption capacity of up to 146 mg/g and stably excellent regeneration for 5 cycles. The mechanism of NH3 adsorption on the in-plane of the γ-AlOOH NSs is explained by the Lewis acid/base theory. The H-bond interactions among the NH3 molecules and the edge groups (-OH) further improve the capture ability of the nanosheets. 相似文献
939.
将CR2032型锂离子电池的制作及电化学性能测试实验设计为大学化学本科生的综合实验并将其应用于本科教学中,建立起基于锂离子电池用正极材料的合成、表征、电极制备及电池组装和性能测试的综合性开放实验。实验以无机材料制备为实验基础,以电化学原理为理论基础,通过文献查阅、确立合成路线、材料制备及表征、锂离子电池制作与测试等多项综合实验内容,使学生了解目前常见的正极材料种类、合成方法、电池的基本结构以及电池性能的测试方法。在教学过程中以学生主动探索为主体,培养学生的科学探究素养,锻炼学生查阅文献、自主设计实验和合作开发的能力。 相似文献
940.
A 2-dimensional gradual period photonic heterostructure was made with holography by use of non-uniform swelling effect of dichromated gelatin during processing. In this structure, the symmetric point group of triangle lattice was debased to C2V from C6V. Theoretical analysis and experimental results show that omnidirectional band gap in visible range can be achieved with this kind of heterostructure made by low refractive index materials. 相似文献