Article
Chemistry, Multidisciplinary
Pooja Chaudhary, Geeta Devi Yadav, Krishna K. Damodaran, Surendra Singh
Summary: New chiral Mn(III)-salen complexes were synthesized and evaluated for the asymmetric epoxidation of styrene, showing high yields and promising catalytic activity; the recovered catalysts could be reused for multiple runs, demonstrating good stability and durability.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Kai Dong, Yuanyuan Wang, Longcheng Zhang, Xiaoya Fan, Zerong Li, Donglin Zhao, Luchao Yue, Shengjun Sun, Yongsong Luo, Qian Liu, Abdulmohsen Ali Alshehri, Quan Li, Dongwei Ma, Xuping Sun
Summary: Renewable electricity-driven organic electrosynthesis processes using electrocatalytically generated H2O2 for olefin epoxidation can efficiently produce high-purity epoxide solutions, with only water and oxygen consumed at ambient conditions.
Article
Chemistry, Multidisciplinary
Yuta Ishikawa, Tatsuya Kameyama, Tsukasa Torimoto, Hajime Maeda, Masahito Segi, Taniyuki Furuyama
Summary: Phthalocyanine ruthenium complexes have been identified as red-light activatable catalysts for trifluoromethylation reactions, enabling the chlorotrifluoromethylation of alkenes without sacrificial reducing reagents. This reaction shows good compatibility with a blue-light-absorbing substrate, unlike traditional photoreaction conditions where the substrate decomposes completely under blue light irradiation.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Mengjun Gong, Yanjun Guo, Daniel Malko, Javier Rubio-Garcia, Jack M. S. Dawson, George J. P. Britovsek, Anthony Kucernak
Summary: Under mild conditions, aldehydes are efficiently converted to epoxides using a heterogeneous Fe-N/C catalyst, which forms the corresponding organic peroxy acid and acylperoxy radicals. Real-time monitoring of oxygen consumption and catalyst potential reveals the formation of peroxy acid and subsequent catalytic epoxidation. The involvement of aldehyde and Fe-N/C catalyst is shown to be the rate determining step for the reaction, and the induction time can be increased by adding a radical scavenger.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Organic
Jinhu Wei, Jie-Sheng Huang, Chi-Ming Che
Summary: The chiral Fe-II(N4) complex developed is an effective chiral Lewis acid for the asymmetric conjugate addition of silyl enol ethers to alpha,beta-unsaturated 2-acyl imidazoles, resulting in high yields and enantioselectivities (up to 99% ee) of chiral 1,5-dicarbonyl synthons and cyclohexenone derivatives.
Article
Chemistry, Multidisciplinary
Rafal Gawin, Andrzej Tracz, Patryk Krajczy, Anna Kozakiewicz-Piekarz, Juan Pablo Martinez, Bartosz Trzaskowski
Summary: Novel ruthenium-based catalysts with rigid spirocyclic alkyl amino carbenes (CAACs) have been developed, showing exceptional stability and high efficiency in the cross-metathesis of fatty acid esters with ethylene. These catalysts enable low loading and achieve remarkable turnover numbers (TON) in the ethenolysis of various substrates.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Dennis Verspeek, Sebastian Ahrens, Anke Spannenberg, Xiaodong Wen, Yong Yang, Yong-Wang Li, Kathrin Junge, Matthias Beller
Summary: A practical manganese(ii) catalyst system with an in situ generating method, using a commercially available bis(2-picolyl) amine ligand, enables efficient epoxidation of terminal aliphatic olefins with tert-butyl hydroperoxide as the oxidant. Crystallization experiments revealed the formation of two manganese solvent complexes with MeCN and H2O, respectively. Furthermore, a detailed investigation of the quinoline additive identified its crucial role in promoting the epoxide formation while negatively affecting its stability.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Takahiko Moteki, Tomohiro Sei, Masaru Ogura
Summary: In the conventional hydrothermal synthesis of porous titanosilicate materials, the aggregation of TiO2 species limits the content of active four-coordinated Ti. However, a bottom-up synthesis using a Ti-incorporated cubic silsesquioxane cage as a precursor allows for a larger incorporation of four-coordinated Ti species in the silica matrix. This method achieves a higher Si/Ti ratio and comparable catalytic activity for the epoxidation reaction.
Article
Chemistry, Multidisciplinary
Andrei Cristian Kuncser, Ioana Dorina Vlaicu, Octavian Dumitru Pavel, Rodica Zavoianu, Mihaela Badea, Dana Radu, Daniela Cristina Culita, Arpad Mihai Rostas, Rodica Olar
Summary: Goethite-based nanocomposites with various compositions were prepared by a soft chemical synthesis method, showing promising catalytic activity in the oxidation of cyclooctene. Among them, 6FeO(OH)·MnO(OH)·0.5H2O (Mn-composite) exhibited the highest catalytic performance.
Article
Energy & Fuels
Chao Xiong, Yichao Liang, Xiantai Zhou, Can Xue, Hongbing Ji
Summary: This article reports the excellent performance of a new Mo-based TiO2 catalyst in the cyclooctene epoxidation reaction, including catalytic activity, reusability, and scalability. The reaction mechanism is also revealed.
Article
Chemistry, Physical
Jeremy W. Arvay, Wei Hong, Christina Li, Fabio H. Ribeiro, W. Nicholas Delgass, James W. Harris
Summary: The catalytic roles of extracrystalline and intracrystalline gold nanoparticles on the direct propylene epoxidation were investigated, and it was found that there was no intrinsic difference between the two. The kinetics of the reaction were measured and the results were consistent with previous studies on intracrystalline gold nanoparticles. An active site model was developed and the estimated turnover frequencies were 20 times higher than previous estimates. The dispersion of gold was found to affect the rate of hydrogen oxidation.
Article
Multidisciplinary Sciences
Yali Zhou, Xingjun Xu, Hongwei Sun, Guanyu Tao, Xiao-Yong Chang, Xiangyou Xing, Bo Chen, Chen Xu
Summary: This study reports effective platinum catalysts for hydroalkoxylation and hydroamination of unactivated alkenes, accommodating various alkene substitution patterns and providing a foundation for rational design of chiral catalysts through detailed mechanistic investigations.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Jeremy W. Arvay, Wei Hong, Christina Li, W. Nicholas Delgass, Fabio H. Ribeiro, James W. Harris
Summary: In this study, the difference in catalytic roles of extracrystalline and intracrystalline gold nanoparticles in direct propylene epoxidation was investigated. The results showed that the activation energy and reaction orders for propylene epoxidation were similar for both types of nanoparticles. However, the activation energy for hydrogen oxidation differed, indicating a change in rate-limiting step or active site. An active site model was developed to estimate catalytic turnover frequencies and it was found that the simultaneous mechanism occurring over proximal Au-Ti sites alone is not sufficient to explain the observed rate of propylene epoxidation, suggesting the kinetically relevant short-range migration of hydrogen peroxide. The study also found that the rates of hydrogen oxidation varied proportionally to the amount of surface gold atoms, indicating the importance of gold dispersion in the catalysts.
Article
Biotechnology & Applied Microbiology
Lili Xu, Yimin Qin, Yufeng Song, Aixing Tang, Youyan Liu
Summary: A green oxidation system containing hydrogen peroxide, Na3C6H5O7, an acyl donor, and glutaraldehyde(GA)-crosslinked cells of Rhizopus oryzae was developed for the epoxidation of alkenes. The catalytic performance of the crosslinked treated cells was substantially improved compared to that of the untreated cells, with a yield of 83% even after four batches of reactions. The addition of Na3C6H5O7 not only eliminates the negative effect of carboxylic acid but also affects the concentration of H2O2, thus impacting the epoxidation reaction.
MICROBIAL CELL FACTORIES
(2023)
Article
Chemistry, Multidisciplinary
Christina Wartmann, Shiny Nandi, Joerg-Martin Neudoerfl, Albrecht Berkessel
Summary: The titanium complex of the cis-1,2-diaminocyclohexane (cis-DACH) derived Berkessel-salalen ligand is a highly efficient and enantioselective catalyst for the asymmetric epoxidation of terminal olefins with hydrogen peroxide. This study also found that this epoxidation catalyst can effectively perform the highly enantioselective hydroxylation of benzylic C-H bonds with hydrogen peroxide. A newly optimized nitro-salalen Ti-catalyst showed the highest efficiency ever reported for asymmetric catalytic benzylic hydroxylation, with enantioselectivities of up to 98% ee, while overoxidation to ketone is marginal. The novel nitro-salalen Ti-catalyst also exhibited enhanced epoxidation efficiency, with a conversion of 1-decene to its epoxide in 90% yield and 94% ee at a catalyst loading of only 0.1mol-%.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Maria Ventura, Jaime Mazario, Marcelo E. Domine
Summary: This study achieved the continuous isomerization of glucose to fructose in aqueous media using a new catalyst based on Ca and Al oxides, showing high conversion and selectivity. The catalyst maintained stable activity during continuous operation and slight deactivation could be overcome by thermal regeneration.
Review
Chemistry, Inorganic & Nuclear
Sofia Friaes, Sara Realista, Henrique Mourao, Beatriz Royo
Summary: This article covers the recent progress in the use of N-heterocyclic carbenes (NHCs) in manganese and rhenium catalysis, with a focus on hydrosilylation, hydrogenation, borrowing hydrogen processes, as well as the electrochemical and photochemical reduction of CO2.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Oscar A. Lenis-Rojas, Beatriz Carvalho, Rui Cabral, Margarida Silva, Sofia Friaes, Catarina Roma-Rodrigues, Marta S. H. Meireles, Clara S. B. Gomes, Jhonathan A. A. Fernandez, Sabela F. Vila, Juan A. Rubiolo, Laura Sanchez, Pedro Baptista, Alexandra R. Fernandes, Beatriz Royo
Summary: The antiproliferative activity of complexes 1 and 2 showed a higher dose-dependent effect on tumor cells, with a 21-fold selectivity towards ovarian carcinoma cells compared to human fibroblasts. Both complexes activate cell death mechanisms by increasing reactive oxygen species, leading to intrinsic apoptosis for complex 2 and autophagy and extrinsic apoptosis for complex 1. They do not target DNA or interfere with cell cycle progression, but they enhance cell migration and new blood vessel formation, suggesting potential applications in early tumor stages and regenerative medicine. Notably, both complexes demonstrated no toxicity in in vivo models.
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
(2022)
Article
Environmental Sciences
S. Jerez, M. Ventura, R. Molina, F. Martinez, M. I. Pariente, J. A. Melero
Summary: The study explored the feasibility of using a Fenton-type process for the pretreatment of oily refinery sludge, finding that adjusting temperature and hydrogen peroxide concentration can effectively decrease TPHs content and increase organic carbon concentration in the liquid phase. The treated aqueous phase showed increased biodegradability, making it suitable for further biological processing in the refinery scheme.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Biochemistry & Molecular Biology
Sofia Friaes, Sara Realista, Clara S. B. Gomes, Paulo N. Martinho, Beatriz Royo
Summary: A series of new [Mn(L)(CO)(3)Br] complexes containing different bidentate chelating ligands have been synthesized and characterized, among which 3 and 4 show the most activity in catalyzing the electroreduction of CO2. Complex 3, with a (NN)-N-AND-based ligand, exhibits good efficiency and selectivity for reducing CO2 to CO in the presence of water, while complex 4, containing a strongly electron donating di-imidazolylidene ligand, shows comparable activity in neat acetonitrile at slightly higher overpotential.
Article
Polymer Science
Andres Cardil, Miguel Palenzuela, Juan F. Vega, Marta E. G. Mosquera
Summary: A recent study has successfully produced nano-sized macromolecular assemblies through a combined polymerization process of glycidyl methacrylate mediated by aluminum complexes. The morphological features and rheological properties of these novel nanoassemblies were investigated. The study revealed that the nanoparticles exhibited a thin disk shape on a flat surface, and their rheological behavior resembled that of un-entangled polymers.
Article
Chemistry, Applied
Henrique Mourao, Clara S. B. Gomes, Sara Realista, Beatriz Royo
Summary: Manganese catalysis, especially with N-heterocyclic carbenes (NHC), has gained attention recently. This study synthesized and characterized new manganese(I) complexes with NHC ligands, which were employed as catalysts for visible light-induced hydrosilylation of ketones. The reaction exhibited high yields and evidence for the involvement of radical intermediates and Mn-H species.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Applied
M. Ventura, D. Puyol, J. A. Melero
Summary: An integrated method combining heterogeneous and biological catalysis has been used to produce biopolymers from lignocellulosic urban solid waste. By optimizing the pre-treatment of waste and using catalysts based on cheap metals, high conversion rates and polymer production have been achieved. The characteristics of the polymer can be controlled by the type of catalyst used.
Article
Polymer Science
Christian Rentero, Jesus Damian, Asier Medel, Maria Fernandez-Millan, Yolanda Rusconi, Giovanni Talarico, Tomas Cuenca, Valentina Sessini, Marta E. G. Mosquera
Summary: By studying the activity and mechanism of two non-toxic potassium compounds as catalysts for the ROP process of LLA, it was found that they can polymerize the monomer quickly, and the molecular structure and solubility of the compounds have certain effects on the polymerization process.
Article
Chemistry, Inorganic & Nuclear
Diego Jaraba Cabrera, Ryan D. Lewis, Carlos Diez-Poza, Lucia Alvarez-Miguel, Marta E. G. Mosquera, Alex Hamilton, Christopher J. Whiteoak
Summary: This study investigates the synthesis of aluminum, gallium, and indium compounds supported by a readily prepared salphen ligand and explores their structures and potential as catalysts for the synthesis of cyclic carbonates. It is demonstrated that the indium compounds are the most active catalysts, despite their lower Lewis acidity compared to aluminum compounds. A Density Functional Theory (DFT) study provides important insights into the reasons for the high activity of the indium catalyst.
DALTON TRANSACTIONS
(2023)
Article
Polymer Science
Miguel Palenzuela, Juan F. Vega, Virginia Souza-Egipsy, Javier Ramos, Christian Rentero, Valentina Sessini, Marta E. G. Mosquera
Summary: In this study, the polymerization of limonene oxide (LO) was optimized using two different aluminium-based catalysts (AlMeX{2,6-(CHPh2)(2)-4-Bu-t-C6H2O}, where X = Me (1), Cl (2)) at room temperature. A bio-based ether, polylimonene oxide (PLO), with low molecular weight and good thermal stability, was successfully synthesized and could be used as a sustainable polymeric additive for bio-based and biodegradable polymers such as polylactic acid (PLA). Blends of PLA and PLO were prepared through melt processing to investigate the influence of PLO on the thermal, mechanical, and morphological properties of PLA. The addition of a small amount of PLO led to a significant decrease in the glass transition temperature of PLA, as well as a decrease in melting temperature and degree of crystallinity, while increasing the flexibility of PLA-based films. These results indicate strong interactions between the components, suggesting partial miscibility.
Review
Chemistry, Organic
Carlos Diez-Poza, Lucia Alvarez-Miguel, Marta E. G. Mosquera, Christopher J. J. Whiteoak
Summary: Cyclic thiocarbonates, sulfur analogues of cyclic carbonates, have been relatively underexplored despite their potential applications and intriguing reactivities. They have been used as monomers for polythiocarbonate synthesis and reactive intermediates for the preparation of sulfur containing compounds. However, the synthesis of these compounds lags behind their non-sulfur analogues. This article provides an overview of the state-of-the-art synthesis and applications of cyclic mono-, di-, and tri-thiocarbonates.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Engineering, Environmental
S. Jerez, J. San Martin, M. Ventura, M. I. Pariente, Y. Segura, D. Puyol, R. Molina, J. A. Melero, F. Martinez
Summary: Oil refineries produce large amounts of refinery wastewater and oily sludge. Conventional treatments handle these effluents separately without considering resource recovery potential. Thermal hydrolysis of oily sludge at different temperatures and times reduces the solid fraction and releases soluble substrates. These hydrolyzed fractions can be used as substrates for the biological treatment of refinery wastewater.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2023)
Article
Chemistry, Organic
Lucia Alvarez-Miguel, Marta E. G. Mosquera, Christopher J. Whiteoak
Summary: The study demonstrates the conversion of erucic acid from rapeseed oil into value-added compounds and presents new methods for synthesizing different cyclic compounds. These compounds have potential applications in the synthesis of bio-based polyurethane.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Materials Science, Biomaterials
Srabanti Ghosh, Georgiana Amariei, Marta E. G. Mosquera, Roberto Rosal
Summary: This study demonstrates the strong antimicrobial activity of conjugated polymer nanostructures (CPNs) as photoactivated compounds against Gram-positive and Gram-negative microorganisms. The effect is attributed to the photoinduced generation of reactive oxygen species, leading to cell membrane damage and inhibition of biofilm formation. The CPNs show potential advantages for biomedical applications due to their broad antibacterial spectrum, biofilm inhibition, and lack of acute toxicity.
JOURNAL OF MATERIALS CHEMISTRY B
(2021)
