Cyclization of propargylic alcohols with CO2 is an important reaction in industry, and noble‐metal catalysts are often employed to ensure the high product yields under environmentally friendly conditions. Herein a porous noble‐metal‐free framework 1 with large 1D channels of 1.66 nm diameter was synthesized for this reaction. Compound 1 exhibits excellent acid/base stability, and is even stable in corrosive triethylamine for one month. Catalytic studies indicate that 1 is an effective catalyst for the cyclization of propargylic alcohols and CO2 without any solvents under mild conditions, and the turnover number (TON) can reach to a record value of 14 400. Furthermore, this MOF catalyst also has rarely seen catalytic activity when the biological macromolecule ethisterone was used as a substrate. Mechanistic studies reveal that the synergistic catalytic effect between CuI and InIII plays a key role in the conversion of CO2. 相似文献
The synthesis of renewable jet fuel from lignocellulosic platform compounds has drawn a lot of attention in recent years. So far, most work has concentrated on the production of conventional jet fuels. JP‐10 is an advanced jet fuel currently obtained from fossil energy. Due to its excellent properties, JP‐10 has been widely used in military aircraft. However, the high price and low availability limit its application in civil aviation. Here, we report a new strategy for the synthesis of bio‐JP‐10 fuel from furfuryl alcohol that is produced on an industrial scale from agricultural and forestry residues. Under the optimized conditions, bio‐JP‐10 fuel was produced with high overall carbon yields (≈65 %). A preliminary economic analysis indicates that the price of bio‐JP‐10 fuel can be greatly decreased from ≈7091 US$/ton (by fossil route) to less than 5600 US$/ton using our new strategy. This work makes the practical application of bio‐JP‐10 fuel forseeable. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - Both uranium and beryllium are very important strategic metals and have been applied to many fields, such as nuclear industries, atomic energy,... 相似文献
Benzofuran has antifungal activity as the inhibitor of N‐myristoyltransferase. Twenty‐nine novel benzofuran‐semicarbazide hybrids were designed and synthesized by principle of drug combinationatory. On this basis, the benzofuran ring was simplified to a resorcinol structure, and sixteen novel 1,3‐dialkoxybenzene‐semicarbazide hybrids were designed and synthesized. All structures of the target compounds were characterized by HRMS and NMR. The in vitro antifungal activity of target compounds was evaluated using the microdilution broth method against eight strains of pathogenic fungi with fluconazole as positive control. According to the results of the target compounds, structure‐activity relationship (SAR) is summarized. The inhibitory activity against the tested strains of simplified compounds ( K01 — K16 ) has different levels improvement compared with compounds Z01 — Z29 . K01 — K16 showed significant antifungal activities against A. fumigatus, C. kruseii, and sensitive C. albicans 5314. Notably, compounds Z20 , Z22 , K10 , K11 and K16 also displayed different activities against two fluconazole‐resistance strains that were isolated from AIDS patients. The minimal inhibitory concentration (MIC) values against fluconazole‐resistant strains were in the range of 2—8 μg/mL and 4—32μg/mL, respectively. Furthermore, molecular docking was performed to investigate the binding affinities and interaction modes between the target compound and N‐myristoyltransferase. 相似文献
A series of efficient ruthenium chloride (RuCl_3)-anchored MOF catalysts,such as RuCl_3@MIL-101 (Cr)-Sal,and RuCl_3@MIL-101 (Cr)-DPPB, have been successfully synthesized by post-synthetic modification (PSM)of the terminal amino of MIL-101(Cr)-NH_2 with salicylaldehyde, 2-diphenylphosphinobenzaldehyde (DPPBde) and anchoring of Ru (Ⅲ) ions. The stronger coordination electron donor interaction between Ru (Ⅲ) ions and chelating groups in the RuCl_3@MIL-101 (Cr)-DPPB enhances its catalytic performance for CO_2 hydrogenation to formic acid. The turnover number (TON) of formic acid was up to 831 in reaction time of 2 h with dimethyl sulfoxide (DMSO) and water (H_2O) as mixed solvent, trimethylamine (Et_3N) as organic base, and PPh_3 as electronic additive. 相似文献
The self-assembly of l-tryptophan on Cu(111) is investigated by an ultrahigh vacuum scanning tunneling microscope (STM) at 4.4 K. When deposited onto the substrate at around 120 K with a coverage of 0.1 monolayer, molecular trimers, tetramers, hexamers, and chains coexist on Cu(111). Then almost all molecules self-assemble into chiral hexamers after being annealed at room temperature. When increasing molecular coverage to the full layer, a new type of chain is observed on the surface. Based on the high-resolution STM images at sub-molecular level, we suggest that the l-tryptophan molecules are present in neutral, zwitterionic or anionic states in these structures. 相似文献
In this study, three different volume expansion ratios of expanded graphite (EG) are prepared and investigated to enhance the heat transfer efficiency of the sodium acetate trihydrate (SAT) composites. A series of SAT composite phase change materials (CPCMs) with EG were prepared. The influence of volume expansion ratio and mass fraction of EG on thermodynamic characteristics of SAT CPCMs was examined, including thermal conductivity, phase change temperature, enthalpy, latent heat storage and release time, and the degree of supercooling. Results showed that SAT CPCMs can be absorbed adequately by EG, and EG could enhance the heat transfer efficiency effectively. But it also brought some problems with the addition of all the three volume expansion ratios of EG, such as the poor enthalpy and serious supercooling. Particularly, the situation gets worse with the increase in mass and expansion ratio of EG. Therefore, it is better to choose the EG with proper expansion ratio or reduce the proportion of the EG which possesses higher expansion ratio. Besides, thermal cycling test and thermogravimetric analysis revealed that the SAT CPCMs with 3 mass% EG showed a good thermal stability.
Quantum chemical calculations are applied to complexes of 6-OX-fulvene (X=H, Cl, Br, I) with ZH3/H2Y (Z=N, P, As, Sb; Y=O, S, Se, Te) to study the competition between the hydrogen bond and the halogen bond. The H-bond weakens as the base atom grows in size and the associated negative electrostatic potential on the Lewis base atom diminishes. The pattern for the halogen bonds is more complicated. In most cases, the halogen bond is stronger for the heavier halogen atom, and pnicogen electron donors are more strongly bound than chalcogen. Halogen bonds to chalcogen atoms strengthen in the order O<S<Se<Te, whereas the pattern is murkier for the pnicogen donors. In terms of competition, most halogen bonds to pnicogen donors are stronger than their H-bond analogues, but there is no clear pattern with respect to chalcogen donors. O prefers a H-bond, while halogen bonds are favored by Te. For S and Se, I-bonds are strongest, followed Br, H, and Cl-bonds in that order. 相似文献