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21.
Yutong Pi Linxia Cui Prof. Wenhao Luo Dr. Haitao Li Dr. Yanfu Ma Dr. Na Ta Xinyao Wang Prof. Rui Gao Prof. Dan Wang Prof. Qihua Yang Prof. Jian Liu 《Angewandte Chemie (International ed. in English)》2023,62(43):e202307096
Mimicking the structures and functions of cells to create artificial organelles has spurred the development of efficient strategies for production of hollow nanoreactors with biomimetic catalytic functions. However, such structure are challenging to fabricate and are thus rarely reported. We report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from a molecular-level design strategy, well-defined hollow multishelled structure phenolic resins (HoMS-PR) and carbon (HoMS-C) submicron particles were accurately constructed. HoMS-C serves as an excellent, versatile platform, owing to its tunable properties with tailored functional sites for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS-C) or externally supported (Pd/HoMS-C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors with size–shape-selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS-C for small aliphatic substrates and Pd/HoMS-C for large aromatic substrates. Theoretical calculations provide insight into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work provides guidance on the rational design and accurate construction of hollow nanoreactors with precisely located active sites and a finely modulated microenvironment by mimicking the functions of cells. 相似文献
22.
Ya-Kui Sun Jin-Bao Qiao Yu-Meng Xin Qin Zhou Zhi-Hua Ma Hui Shao Yu-Ming Zhao 《Angewandte Chemie (International ed. in English)》2023,62(40):e202310917
Herein, we report a concise and divergent synthesis of the complex hasubanan alkaloids metaphanine and oxoepistephamiersine from commercially available and inexpensive cyclohexanedione monoethylene acetal. Our synthesis features a palladium-catalyzed cascade cyclization reaction to set the tricyclic carbon framework of the desired molecules, a regioselective Baeyer–Villiger oxidation followed by a MeNH2 triggered skeletal reorganization cascade to construct the benzannulated aza[4.4.3]propellane, and a strategically late-stage regio-/diastereoselective oxidative annulation of sp3 C−H bond to form the challenging THF ring system and hemiketal moiety in a single step. In addition, a highly enantioselective alkylation of cyclohexanedione monoethylene acetal paved the way for the asymmetric synthesis of target molecular. 相似文献
23.
Shiyi Wei Prof. Fei Wu Dr. Jing Liu Dr. Wenliang Ji Dr. Xiulan He Ran Liu Prof. Ping Yu Prof. Lanqun Mao 《Angewandte Chemie (International ed. in English)》2023,62(52):e202315681
Nanoplastics are recently recognized as neurotoxic factors for the nervous systems. However, whether and how they affect vesicle chemistry (i.e., vesicular catecholamine content and exocytosis) remains unclear. This study offers the first direct evidence for the nanoplastics-induced neurotoxicity by single-vesicle electrochemistry. We observe the cellular uptake of polystyrene (PS) nanoplastics into model neuronal cells and mouse primary neurons, leading to cell viability loss depending on nanoplastics exposure time and concentration. By using single-vesicle electrochemistry, we find the reductions in the vesicular catecholamine content, the frequency of stimulated exocytotic spikes, the neurotransmitter release amount of single exocytotic event, and the membrane-vesicle fusion pore opening-closing speed. Mechanistic investigations suggest that PS nanoplastics can cause disruption of filamentous actin (F-actin) assemblies at cytomembrane zones and change the kinetic patterns of vesicle exocytosis. Our finding shapes the first quantitative picture of neurotoxicity induced by high-concentration nanoplastics exposure at a single-cell level. 相似文献
24.
由1,1'-双苄基-3,3'-氧双(亚乙基-2,1)-二苯并咪唑六氟磷酸盐(L1)和1,1'-双(吡啶-2-甲基)-3,3'-氧双(亚乙基-2,1)-二苯并咪唑六氟磷酸盐(L2)为配体合成了[Hg(C32H28N4O)](CH3COO)(PF6)2(1)和[NiCl(C30H28N6O)](PF6)2(2),并对其进行了结构表征。配合物1是一个罕见的三价态Hg配合物,为单斜晶系P21/c空间群,配合物2为单斜晶系P21/n的配合物。1和2中存在O-H…F,C-H…F,C-H…Cl,C-H…π,P-F…π氢键作用和π-π堆积作用,并以此分别形成了3D超分子结构。 相似文献
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Li Wang Yu-Qian Chi Wen-Bin Ouyang Zhen Zang Sheng-Xiong Huang 《Natural product research》2015,29(15):1406-1413
A new myrsinol-type diterpene polyester, 14-deoxo-3β-O-propinoyl-2α,5α,7β,15β-tetra-O-acetyl-14α-O-benzoyl-myrsinol (1), and its known analogue, 14-deoxo-3β-O-prorionyl-5α,15β-di-O-acetyl-7β-O-nicotinoyl-myrsinol-14β-acetate (2), together with a monoterpenoid, pubinernoid A (3), two indole alkaloids, neoechinulin A (4) and dihydroxyisoechinulin A (5), two benzene derivatives, siringin (6) and (3-methoxyphenyl) acetic acid (7), were isolated from the 70% acetone extract of the aerial parts of Euphorbia dracunculoides Lam. Their structures were elucidated on the basis of spectroscopic evidence and comparison with literature reports. The absolute configuration of 1 was deduced by comparing experimental and calculated ECD spectra. Among them, compounds 4 and 5 were first obtained from the plant source. In addition, the 13C NMR data of compound 2 was reported for the first time. 相似文献
28.
Kukhtin-Ramirez反应是有机化学中一类重要的极性反转反应.利用三价磷的还原性对α-羰基酮化合物进行极性反转,所生成的Kukhtin-Ramirez活性中间体在诸多转化中都展现出了其作为1,1-偶极子的化学性质.近年来关于该活性中间体的反应研究主要包括:极性X—H键插入反应、还原性加成反应、形式[2+1]环加成反应、形式[4+1]环加成反应、形式[4+2]环加成反应.这些转化为一些重要的多官能团化合成中间体及结构复杂的环状化合物提供了高效简洁的合成方法,凸显了Kukhtin-Ramirez极性反转反应在有机合成中的重要性. 相似文献
29.
我们通过原位还原的方法将吸附在g-C3N4表面上Cu2+还原,制备出Cu2O/g-C3N4复合材料,并利用XRD、SEM、FT-IR、XPS等分析手段表征Cu2O/g-C3N4.表征结果显示:Cu元素主要以Cu2O的形式吸附在g-C3N4载体上.另外,还考察了Cu2O/g-C3 N4在“一锅法”合成吲哚-2-甲酸乙酯的反应中的催化性能.结果表明:即使在较低的催化担载量和温和的反应条件下,Cu2O/g-C3 N4仍能表现出良好的催化性能并获得44.1%的收率. 相似文献
30.
H is called an ? p -embedded subgroup of G, if there exists a p-nilpotent subgroup B of G such that H p ∈ Syl p (B) and B is ? p -supplemented in G. In this paper, by considering prime divisor 3, 5, or 7, we use ? p -embedded property of primary subgroups to investigate the solvability of finite groups. The main result is follows. Let E be a normal subgroup of G, and let P be a Sylow 5-subgroup of E. Suppose that 1 < d ? |P| and d divides |P|. If every subgroup H of P with |H| = d is ?5-embedded in G, then every composition factor of E satisfies one of the following conditions: (1) I/C is cyclic of order 5, (2) I/C is 5′-group, (3) I/C ? A5. 相似文献