Search

A Cu/Co tandem catalysis protocol was developed to conduct the hydroformylation of olefins using CO2/H2 and PMHS (polymethylhydrosiloxane) as a readily available and environmentally friendly hydride source. This methodology was performed via a two‐step approach consisting of the copper‐catalyzed reduction of CO2 by hydrosilane and subsequent cobalt‐promoted hydroformylation with H2 and the in situ formed CO. The optimized triphos oxide ligand, which presumably facilitates the migratory insertion of CO gives moderate to excellent yields for both terminal and internal alkenes. This earth‐abundant metal catalysis provides a reliable and efficient way to afford useful aldehydes in industry using silicon by‐product PMHS as hydrogen source and renewable CO2 as carbonyl source. [ABSTRACT FROM AUTHOR]

Designing earth‐abundant metal complexes as efficient molecular photocatalysts for visible light‐driven CO2 reduction is a key challenge in artificial photosynthesis. Here, we demonstrated the first example of a mononuclear iron pyridine‐thiolate complex that functions both as a photosensitizer and catalyst for CO2 reduction. This single‐component bifunctional molecular photocatalyst efficiently reduced CO2 to formate and CO with a total turnover number (TON) of 46 and turnover frequency (TOF) of 11.5 h−1 in 4 h under visible light irradiation. Notably, the quantum yield was determined to be 8.4 % for the generation of formate and CO at 400 nm. Quenching experiments indicate that high photocatalytic activity is mainly attributed to the rapid intramolecular quenching protocol. The mechanism investigation by DFT calculation and electrochemical studies revealed that the protonation of Febpy(pyS)2 is indispensable step for photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

A series of KF/Mg‐Fe oxides were fabricated via the solid‐state reaction between KF and Mg‐Fe oxides. Especially, when 20 wt % KF was supported on the Mg‐Fe bi‐metal oxides and calcined at 400–600 °C, the solid material with more basic sites than the support itself was obtained. When applied as catalyst to dimethyl carbonate (DMC) synthesis through transesterification of ethylene carbonate (EC) and methanol, this material can afforded up to 88 % yield and 97 % selectivity toward DMC in 2 h under reflux conditions with the molar ratio of methanol to ethylene carbonate set at 8. It is worth noting that the catalyst was easily separated and reused, retaining at least 89 % catalytic activity during the first four recycles. Although an attenuated activity was still observed due to the inevitable filtration loss and dissolution, this solid base can still provide clues to the development recyclable catalyst in green synthesis of DMC. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fragrant rice is increasingly popular with the public owing to its fresh aroma, and 2‐acetyl‐1‐pyrroline (2‐AP) is the main characteristic component of the aroma in fragrant rice. Rice–fish co‐culture is an environmentally friendly practice in sustainable agriculture. However, the effect of rice–fish co‐culture on 2‐AP in grains has received little study. A conventional fragrant rice (Meixiangzhan 2) was used, and a related field experiment during three rice growing seasons was conducted to investigate the effects of rice–fish co‐culture on 2‐AP, as well as the rice quality, yield, plant nutrients, and precursors and enzyme activities of 2‐AP biosynthesis in leaves. This study involved three fish stocking density treatments (i.e. 9000 (D1), 15 000 (D2), and 21 000 (D3) fish fries per hectare) and rice monocropping. RESULTS: Rice–fish co‐culture increased the 2‐AP content in grains by 2.5–49.4% over that of the monocropping, with significant increases in the early and late rice seasons of 2020. Rice–fish co‐culture treatments significantly promoted seed‐setting rates by 3.39–7.65%, and improved leaf nutrients and rice quality. Notably, the D2 treatment significantly increased leaf total nitrogen (TN), total phosphorus (TP), and total potassium (TK) contents and the head rice rate at maturity stage, while significantly decreased chalkiness degree. There was no significant difference in rice yield. CONCLUSION: Rice–fish co‐culture had positive effects on 2‐AP synthesis, rice quality, seed‐setting rates, and plant nutrient contents. The better stocking density of field fish for rice–fish co‐culture in this study was 15 000 fish ha−1. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Biomass‐based polymers and their property regulation using functional materials have attracted much interest. In this work, ricinoleic acid‐derived cyclic carbonate was prepared and applied to the synthesis of nonisocyanate polyurethane (NIPU) with aliphatic diamine, in which octa(aminopropyl) polyhedral oligomeric silsesquioxane (OAP‐POSS) was incorporated as polyamine to partially or totally substitutes for the diamine to introduce POSS units into the polymer thus regulating the properties of the resultant material. In the curing process, Fourier transform infrared spectroscopy (FT‐IR) was used to track the reaction and curing at 50°C for 12 h was found to be sufficient for the polymerization. A series of POSS modified NIPUs were obtained by altering the molar fraction of OAP‐POSS in total amine components and the material with the highest thermal stability, shore hardness and water resistance was accessed with 100% substitution of OAP‐POSS for diamine. [ABSTRACT FROM AUTHOR]

Capturing CO2 and subsequently converting into valuable chemicals has attracted extensive attention. Herein, a series of biomass‐based N‐rich porous carbon materials with high specific surface area and pore volume were prepared using biomass waste soybean dregs as precursors. The nitrogen content was up to 4 % with different forms in the carbon skeleton such as pyridine‐N, pyrrole‐N. The synergistic effect of ultra‐micropore (pore size <0.7 nm) and N‐containing groups endowed the materials with a high CO2 adsorption capacity, reaching 6.3 and 3.6 mmol g−1 at 0 and 25 °C under atmospheric pressure, respectively. In addition, the sufficient interaction between N‐containing groups and CO2 was demonstrated by solid‐state nuclear magnetic resonance spectroscopy, and the captured CO2 was possibly activated in the form of carbamate, which is conducive to subsequent conversion. Therefore, the supported catalyst with the as‐synthetic porous carbon material as the carrier and ZnII as catalytic sites was prepared and successfully applied for carboxylative cyclization of propargylic amine with CO2 to afford the 3‐benzyl‐5‐methyleneoxazolidin‐2‐one. The results showed that CO2 capture and in‐situ conversion work effectively to produce highly value‐added chemicals. In this process, the captured CO2 could be activated and fixed into chemicals in mild conditions. More importantly, the energy consumption in CO2 desorption and adsorbent regeneration could be avoided. The valorization of both solid waste and CO2 to valuable chemicals provides an elegant strategy of killing three birds with one stone. [ABSTRACT FROM AUTHOR]

In this work, the novel solid base Li/NaY was prepared via the solid state reaction between NaY zeolite and Li2CO3 at high temperature. When applied to the dimethyl carbonate (DMC) preparation through transesterification of ethylene carbonate (EC) and methanol, up to 89% yield of DMC with 99% selectivity can be accessed. The characterization results reveal the as‐synthesized Li/NaY possesses higher basicity than NaY. Furthermore, the Lewis acidity of the Li/NaY material is also enhanced due to the incorporation of lithium. Therefore, the Li/NaY can act as a dual functional catalyst in the transesterification reaction, thus leading to high efficiency. Notably, this catalyst can be easily recovered and reused for at least six times without obvious activity loss. This work provides a green synthetic route to DMC production and also sheds light on the development of solid basic catalysts. [ABSTRACT FROM AUTHOR]

Bio‐derived lubricants, especially those derived from vegetable oils, are considered to be promising alternatives to mineral oil‐based lubricants due to the features of sustainability and environmental friendliness. In this work, the polyol ricinoleates were prepared by esterification of ricinoleic acid with trimethylolpropane (TMP), neopentyl glycol (NPG) and pentaerythritol (PE) respectively using Lewis acidic stannous oxide as an efficient heterogeneous catalyst, affording the polyol ricinoleates up to 99.7% yield. Remarkably, the solid catalyst was readily recovered and reused at least for five cycles without significant loss of activity. The resulting polyol ricinoleates products were structurally characterized by Fourier transform infrared spectroscopy (FT‐IR), 1H NMR, 13C NMR, electrospray ionization mass spectra (ESI‐MS); and were stable below 300°C through thermogravimetric analysis (TGA). Furthermore, the physicochemical and lubricating properties of as‐synthesized polyol esters were also evaluated including viscosity at 40 and 100°C, viscosity index (VI), pour point and flash point, thermal stability and wear scar diameter. To our delight, the performance indicators of the target products were comparable or better than the commercial lubricants, showing their potential as lubricant base oil. This work represents an alternative access to useful lubricant products via effective and selective conversion of non‐edible vegetable oil. [ABSTRACT FROM AUTHOR]

Abstract: The development of efficient catalysts for the alkylation of amines with carboxylic acids is attracting much attention. Herein, we would like to report an earth‐abundant iron‐catalyzed protocol for the N‐alkylation of anilines using carboxylic acid as alkyl source and phenylsilane as reducing agent. With Fe2(CO)9 as a catalyst, a broad range of primary and secondary anilines are successfully converted to the corresponding tertiary anilines. Furthermore, this N‐alkylation mainly goes through the amide pathway; while the aldehyde pathway can not be ruled out. [ABSTRACT FROM AUTHOR]

Abstract: In the last few years, photochemical and electrochemical CO2 transformations have attracted increasing attention in response to topical interest in renewable energy and green chemistry. The present minireview offers an overview about the current approaches for the photochemical and electrochemical carbon dioxide fixation with organic compounds. Valuable products, including carboxylic acids and heterocyclic compounds, are accessible through carboxylation and carboxylative cyclization, respectively. In photochemical and electrochemical processes, photo‐ or electro‐induced radical ions or other high‐energy organic compounds are considered as key intermediates to react with CO2. Besides, activation of CO2 to produce radical anion has also been reported. [ABSTRACT FROM AUTHOR]

Background We investigated risk factors for decreased lung function among Chinese island residents (≥30 years) to determine the relationship between metabolic syndrome (MS) and decreased lung function. Methods From October 17, 2011 to November 1, 2011, 2607 residents aged ≥30 years who lived on the Huangqi Peninsula of Fujian were enlisted by random cluster sampling. They completed a questionnaire designed according to the Burden of Obstructive Lung Disease (BOLD) questionnaire, and underwent physical examination, blood test, and lung function evaluation. We constructed spirometric prediction equations for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), determined the lower limits of normal for FVC, FEV1 and FEV1/FVC, and examined the relationship between lung function and MS. Results Prediction equations for normal island residents were as follows: FVC (L) = −0.023 × age (years) + 0.042 × height (cm) + 0.641 × weight (kg) - 3.607 (males);, FVC (L) = −0.017 × age (years) + 0.030 × height (cm) + 0.009 × weight (kg) - 1.741 (females);, FEV1 (L) = −0.023 × age (years) + 0.040 × height (cm) + 0.010 × weight (kg) - 2.999 (males);, FEV1 (L) = −0.017 × age (years) + 0.026 × height (cm) + 0.007 × weight (kg) −1.135 (females)., The odds ratio for MS for increased risk of decreased FVC was 4.623 (95%CI =3.626-5.894, P<0.001), and for increased risk of decreased FEV1 was 3.043 (95%CI =2.447-3.785, P<0.001). Conclusions MS is a risk factor for decreased lung function in island residents ≥30 years old. [ABSTRACT FROM AUTHOR]

Inside Back Cover picture shows The carps trying hard to make a successful jump over the Dragon Gate will change into fish‐dragons, which is a legend handed down in China over generations. The back cover picture shows photochemical and electrochemical CO2 transformations with organic compounds through the utilization of solar energy or electric energy, producing a series of valuable products, including carboxylic acids and hetero‐cyclic compounds. The combined utilization of both clean energy and CO2 has attracted increasing attention in sustainable development of renewable energy and green chemistry. Recent advances are summarized by He et al. on page 644–659. [ABSTRACT FROM AUTHOR]