High enantioselectivity (80-92% enantiomeric excess (ee)) has been obtained for the epoxidation of various styrenes using an easily prepared ketone (4) catalyst.
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http://dx.doi.org/10.1021/jo0520285 | DOI Listing |
Polymers (Basel)
December 2024
Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang'an University, South 2nd Ring Road Middle Section, Xi'an 710064, China.
Studying the mechanisms and effects of rejuvenators on SBS-modified bitumen is crucial for repairing degraded SBS and recycling aged SBS-modified bitumen (ASMB), thereby contributing to the sustainable development of bitumen pavements. This research examines the roles of mono-epoxy Alkyl (C12-C14) glycidyl ether (AGE) and di-epoxy 1,6-Hexanediol diglycidyl ether (HDE) under the catalysis of N,N-dimethyl benzyl amine (BDMA) in repairing degraded SBS chains. Aromatic oil (ORSMB)-, AGE-aromatic oil (ARSMB)-, and HDE-aromatic oil (HRSMB)-rejuvenated bitumen are analyzed for their chemical structures, physical properties, and rheological properties.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos 38834, Greece. Electronic address:
The coupling of carbon dioxide (CO) with epoxides to produce cyclic carbonates is a desirable decarbonization approach, but its commercial applicability is still restricted by the costly catalysts required, as well as the need for high temperature and high pressure. Herein, oxygen vacancy-rich defective tungsten oxide (WO) rich in Lewis acid sites was modified by Prussian blue (PB), and the obtained composite reaches up to 94 % styrene carbonate yield (171 mmol gh) at ambient temperature and pressure, exhibiting outstanding advantages in the photocatalytic CO cycloaddition reaction compared with currently reported photocatalysts. It is found that the introduction of PB with photothermal properties significantly enhances the capability of WO to absorb and activate CO and epoxide, along with its light utilization ability.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
State Key Laboratory Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Road South, Nanjing 211816, China.
The cycloaddition of CO to epoxide (CCE) reactions produce valuable cyclic carbonates useful in the electrolytes of lithium-ion batteries, as organic solvents, and in polymeric materials. However, halide-containing catalysts are predominantly used in these reactions, despite halides being notoriously corrosive to steel processing equipment and residual halides also having harmful effects. To eliminate the reliance on halides as cocatalyst in most CCE reactions, halide-free catalysts are highly desirable.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Graduate Program in Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil; Institute of Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil. Electronic address:
The objective of this study was to produce new and renewable bio-based plasticizers from used soybean cooking oil (USCO). First, USCO was completely converted into free fatty acids (FFAs) using lipase from Candida rugosa. Next, these FFAs were enzymatically esterified with benzyl alcohol in solvent-free systems.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Institute of Physical Chemistry-Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania.
Bimetallic (Ta/Ti, V, Co, Nb) mesoporous MCM-41 nanoparticles were obtained by direct synthesis and hydrothermal treatment. The obtained mesoporous materials were characterized by XRD, XRF, N adsorption/desorption, SEM, TEM, XPS, Raman, UV-Vis, and PL spectroscopy. A more significant effect was observed on the mesoporous structure, typically for MCM-41, and on optic properties if the second metal (Ti, Co) did not belong to the same Vb group with Ta as V and Nb.
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