Article
Chemistry, Multidisciplinary
Feixiang Sun, Xin Chen, Siyi Wang, Fan Sun, Sheng-Yin Zhao, Weiping Liu
Summary: In this study, a manganese-catalyzed three-component coupling reaction was reported for the synthesis of gamma-hydroxy phosphines via a borrowing hydrogen strategy. Methanol serves as a sustainable C1 source and the reaction delivers the desired products in good yields.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Martin Soto, Vicente Gotor-Fernandez, Humberto Rodriguez-Solla, Walter Baratta
Summary: The transfer hydrogenation of flavanones and ortho-hydroxychalcones catalyzed by ruthenium pincer complexes allows the synthesis of ortho-hydroxy 1,3-diarypropanols with high yield and selectivity. The amount of co-catalyst is crucial for the reduction reaction, while using pincer catalysts with specific ligands can achieve high enantiomeric excess and moderate conversion rates in the reduction of flavanones.
Article
Chemistry, Inorganic & Nuclear
Dariusz Lewandowski, Grzegorz Hreczycho
Summary: A hydroboration reaction of alkenes is catalyzed using an inexpensive cobalt pincer complex based on a PN5P triazine backbone. This protocol enables efficient anti-Markovnikov functionalization of alkenes with various functional groups under mild conditions, resulting in high yields. Selectivity towards vinylsilyl groups distinguishes them from other alkenyl or alkyne groups, leading to the synthesis of bifunctional compounds with potential applications in advanced materials.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Inorganic & Nuclear
Ranjeesh Thenarukandiyil, Rohit Kamte, Subhash Garhwal, Philipp Effnert, Natalia Fridman, Graham de Ruiter
Summary: Acceptorless alcohol dehydrogenation is a powerful reaction for sustainable synthesis. In this study, efficient manganese-catalyzed a-methylation of ketones and indoles was reported, which supports a diverse set of functional groups and provides excellent yields. The use of methanol as a green and renewable feedstock increases the sustainability of the acceptorless dehydrogenation.
Article
Chemistry, Organic
Nandita Biswas, Rahul Sharma, Bitan Sardar, Dipankar Srimani
Summary: SNS-based ruthenium pincer catalysts were used to successfully achieve Guerbet condensation reaction, resulting in good yields of beta-alkylated dimeric alcohols. Additionally, the catalytic ability of these complexes to convert ethanol into butanol was investigated. The study was further extended to the C-alkylation of secondary alcohols with primary alcohols, leading to the synthesis of alpha-alkylated ketones, and control experiments indicated the involvement of borrowing hydrogen in the reaction mechanism.
Article
Chemistry, Inorganic & Nuclear
Viktoriia Zubar, Aleksandra Brzozowska, Jan Sklyaruk, Magnus Rueping
Summary: A new manganese-catalyzed heterocyclization of aminoalcohols has been developed, leading to a wide range of heterocycles including tetrahydroquinolines, dihydroquinolinones, and tetrahydro-1H-benzo[b]azepines. The reaction is conducted under mild conditions using air and moisture stable manganese catalysts, resulting in good to excellent yields of the desired heterocycles.
Article
Chemistry, Multidisciplinary
Han-Jun Ai, Yang Yuan, Xiao-Feng Wu
Summary: In this work, a pincer ruthenium-catalyzed heterocycle compatible alkoxycarbonylation of alkyl iodides has been developed, allowing efficient reaction with a variety of heterocyclic substrates.
Article
Chemistry, Inorganic & Nuclear
Vinay Arora, Himani Narjinari, Akshai Kumar
Summary: In this study, a series of NNN pincer-nickel complexes based on bis(imino)pyridine ligands were synthesized and characterized, showing promising results in catalyzing beta-alkylation reactions of alcohols with benzyl alcohols with high yields and unprecedented turnovers. The catalytic system exhibited zero-order dependence on catalyst concentration and first-order dependence on base and substrate concentrations, indicating a base-mediated aldol condensation as the rate-determining step. HRMS analysis identified most of the intermediates involved in the catalytic process, making it the first report of pincer-Ni catalyzed beta-alkylation of alcohols with such high turnovers using a homogeneous molecular nickel-based catalyst.
Article
Chemistry, Organic
Steffen Skowaisa, Edgar Haak
Summary: A highly effective catalyst for the alkylation of poorly reactive alcohols with indoles or ketones has been discovered. This catalyst is readily available, stable in air and moisture, and exhibits wide functional group tolerance.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Yuguang Wang, Hengliang Liu, Donglin Cai, Jinqiu Zhou, Mengjing Wu, Huifang Zheng, Deming Xie
Summary: A high-performance and recyclable high valence oxides of ruthenium catalyst was successfully released from commercially available ruthenium carbon catalyst. It selectively oxidized C=C bonds and C equivalent to C bonds to yield corresponding aldehydes, ketones, and alpha-diketones with high yields. The catalyst, with its cheap availability, recyclability, safety, and low toxicity, shows great potential in industrial scale unsaturated bond oxidation cleavage applications.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jonas Bosken, Rafael E. Rodriguez-Lugo, Sven Nappen, Monica Trincado, Hansjorg Grutzmacher
Summary: This study reports the first homogeneous catalyst that effectively reduces nitrous oxide using readily available and cheap light alcohols as reducing agents. The reaction proceeds by converting the alcohols into carboxylate derivatives and N2O into N-2 and H2O. The reaction is catalysed by the low-valent dinuclear ruthenium complex [Ru2H(mu-H)(Me(2)dad)(dbcot)(2)].
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Bedraj Pandey, Jeanette A. Krause, Hairong Guan
Summary: This study reports a new Pincer ligand system and its catalytic activity and stability in catalytic hydrogenation and dehydrogenation reactions.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Lina Geng, Mingchao Zhang, Zhiqiang Zhang, Yan Li
Summary: Based on density functional theory calculations, we have investigated the mechanism of ruthenium pincer complex-catalyzed dehydrogenation of methanol to CO and H2. Our results suggest that the reaction proceeds through three stages and the energetically favorable cycle involves methoxymethanol as the substrate. Additionally, we propose a different mechanism for the decarbonylation step in the cycle, contrary to the previously proposed mechanism.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Lina Geng, Mingchao Zhang, Zhiqiang Zhang, Yan Li
Summary: The mechanism of the dehydrogenation of methanol to CO and H2 catalyzed by a ruthenium pincer complex has been studied using density functional theory (DFT). Two cycles, one with methanol and the other with methoxymethanol, were analyzed. The results showed that both cycles consist of three stages and the energetically more feasible cycle is the one with methoxymethanol. In addition, an alternative pathway for the decarbonylation stage was proposed and examined.
DALTON TRANSACTIONS
(2023)
Review
Chemistry, Inorganic & Nuclear
Tingting Liu, Liandi Wang, Kaikai Wu, Qingfu Wang, Zhengkun Yu
Summary: This article provides a summary of the synthesis and organic synthetic applications of various pincer-type ruthenium(II) complexes. These complexes showed high catalytic activities in transfer hydrogenation of ketones, C-C bond formation from alcohols and ketones, and dehydrogenation reactions. The catalytically active intermediates for these transformations were identified as RuH complexes. The review covers mononuclear ruthenium(II) pincer complexes for (asymmetric) transfer hydrogenation of ketones, multinuclear ruthenium(II) complexes for transfer hydrogenation of ketones, and mononuclear ruthenium(II) complexes for other reactions such as Oppenauer-type oxidation, beta-alkylation of secondary alcohols, synthesis of multisubstituted heterocycles, and acceptorless dehydrogenation of N-heterocycles and secondary alcohols.
INORGANICA CHIMICA ACTA
(2023)
Article
Chemistry, Physical
Huaizhou Yang, Xiaotian Zhu, Helda Wika Amini, Boy Fachri, Majid Ahmadi, Gert H. ten Brink, Peter J. Deuss, Hero J. Heeres
Summary: This study focuses on the selective demethoxylation of guaiacol using Cu-based catalysts supported on various materials. Cu/TiO2-P25 was found to be the most effective and stable catalyst, converting 98% of guaiacol to demethoxylated phenols with a selectivity of 87%. It was also observed that the oxygen storage capacity of the support material played a role in the catalytic cycle. The successful demethoxylation of 4-n-propylguaiacol and guaiacol-rich feed from pyrolysis oil was demonstrated.
APPLIED CATALYSIS A-GENERAL
(2023)
Article
Engineering, Environmental
Homer C. Genuino, M. Pilar Ruiz, Hero J. Heeres, Sascha R. A. Kersten
Summary: The predictability of pyrolysis yields and product composition of mixed plastics was studied. A linear model was developed to predict the pyrolysis yields and oil/wax composition of mixed feeds based on the pyrolysis results of individual feedstocks, showing a reasonable prediction accuracy. However, the presence of significant amounts of PET in the mixed plastic streams negatively affected the condensable product production and promoted the formation of solid products. Furthermore, the prediction accuracy of the aromatic carbon yield in the condensable product was limited due to the behavior of PET.
Article
Chemistry, Physical
J. O. P. Broekman, Homer C. C. Genuino, Hero J. J. Heeres, Jelle Brinksma, Thomas Wielema, Peter J. J. Deuss
Summary: Oxidation is an effective method to enhance the properties of native starches, and the use of a commercial homogeneous binuclear manganese catalyst and H2O2 as the oxidant can achieve oxidation without generating ecotoxic waste products. This catalytic oxidation of starch at ppm loadings yields starch with similar properties as those achieved by NaOCl oxidation. This highlights the potential for a more sustainable process to produce oxidized starches.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Soumyadeep Chakrabortty, Katharina Konieczny, Felix J. de Zwart, Eduard. O. Bobylev, Eszter Barath, Sergey Tin, Bernd H. Mueller, Joost N. H. Reek, Bas de Bruin, Johannes G. de Vries
Summary: Researchers achieved enantioselective hydrogenation of cyclic enamides using an earth-abundant cobalt-bisphosphine catalyst. The catalytic system, CoCl2/(S,S)-Ph-BPE, reduced trisubstituted carbocyclic enamides to saturated amides with high activity and excellent enantioselectivity (up to 99%). The methodology can be extended to the synthesis of chiral amines by base hydrolysis of the hydrogenation products. Preliminary mechanistic investigations suggested a sigma-bond-metathesis pathway for the hydrogenation of the carbon-carbon double bond, involving a high spin cobalt (II) species.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Soumyadeep Chakrabortty, Shasha Zheng, Fabian Kallmeier, Eszter Barath, Sergey Tin, Johannes G. de Vries
Summary: A readily available chiral Ru/bisphosphine catalyst was used to achieve the direct asymmetric reductive amination of bio-based levulinic acid (LA) to produce enantioenriched 5-methylpyrrolidinone with excellent enantioselectivity (up to 96% ee) and high isolated yield (up to 89%). Methyl levulinate (ML), a byproduct from the industrial production of 2,5-furandicarboxylic acid (FDCA), can be used as a substitute for LA with similar reactivity and selectivity. Mass spectrometry and isotope labelling studies suggest that the chiral lactam is formed through imine-enamine tautomerization/cyclization followed by asymmetric hydrogenation of the cyclic enamide.
Article
Energy & Fuels
Stef Ghysels, Jan Verwaeren, Hero Jan Heeres, Leon Rohrbach, Simon Backx, Sven Mangelinckx, Frederik Ronsse
Summary: Pyrolysis liquids are difficult to analyze comprehensively due to their complex and heterogeneous composition. The use of two-dimensional 1H-13C heteronuclear single-quantum correlation (HSQC) nuclear magnetic resonance (NMR) has gained renewed interest for quantitative recording, providing a valuable tool for fingerprinting and assessing these complex liquids. However, data analysis of 1H-13C HSQC spectra has been lacking behind recent experimental developments. This study explores and demonstrates a new approach for automated data analysis from 1H-13C HSQC spectra using image processing tools.
Article
Chemistry, Analytical
Homer C. Genuino, Ludovico Contucci, Jessi Osorio Velasco, Balaji Sridharan, Erwin Wilbers, Okan Akin, Josef G. M. Winkelman, Robertus H. Venderbosch, Hero J. Heeres
Summary: This study investigated the pyrolysis of LignoBoost lignin in a molten salt solution and found that the presence of salt had a positive influence on the liquid phase yields and composition, with higher levels of depolymerization and selectivity to aromatic and phenolic monomers.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Chemistry, Multidisciplinary
Chencong Ruan, Hero Jan Heeres, Jun Yue
Summary: In this study, a biphasic system of MIBK-DES was used to convert fructose to HMF, resulting in an enhanced HMF yield of 63% compared to 48% in the monophasic DES system. The results obtained in capillary microreactors confirmed the slight mass transfer limitation and showed similar performance to batch reactors.
JOURNAL OF FLOW CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Huaizhou Yang, Idoia Hita, Zhiwen Wang, Jozef G. M. Winkelman, Peter J. Deuss, Hero J. Heeres
Summary: This study reports the use of nonprecious metal-based catalysts for the catalytic hydrotreatment of technical lignins to obtain oils enriched in biobased chemicals. The best result was achieved using a monometallic Ni catalyst with an ordered mesoporous alumina support doped with Ti, giving an oil yield of 57 wt% with 10 wt% alkylphenols on lignin intake. It was shown that the mesoporous structure of alumina is crucial for enhanced lignin oil yields.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Engineering, Chemical
J. O. P. Broekman, Brian W. Dijkhuis, Johanna A. Thomann, Andre Heeres, Hero J. Heeres, Peter J. Deuss
Summary: Modified starches used in the food industry often lack important minerals like magnesium. This study focused on introducing magnesium into oxidized potato starch using dibasic magnesium hypochlorite (DMH). The addition of magnesium changed the pasting properties of starch and increased gelatinization temperature, potentially due to an ionic cross-linking effect. The properties were reversible through metal cation exchange, offering potential health benefits.
Article
Engineering, Chemical
Angela Martina, Gorjan Stojkov, Henk H. van de Bovenkamp, Ting Wang, Peter J. Deuss, Inge W. Noordergraaf, Jozef G. M. Winkelman, Francesco Picchioni, Hero J. Heeres
Summary: This study investigates the conversion of D-AHG, one of the main building blocks of seaweed polysaccharides, to HMF and LA using sulfuric acid as a catalyst in water. The findings indicate that D-AHG is a good precursor for HMF synthesis and the highest yields of HMF and LA were obtained under specific conditions.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Biochemistry & Molecular Biology
Kyzgaldak Ramazanova, Soumyadeep Chakrabortty, Fabian Kallmeier, Nadja Kretzschmar, Sergey Tin, Peter Loennecke, Johannes G. de Vries, Evamarie Hey-Hawkins
Summary: Sulfur-protected enantiopure P-chiral 1-phosphanorbornane silyl ethers 5a,b were obtained in high yields via reaction with tert-butyldimethylsilyl chloride (TBDMSCl) and triphenylsilyl chloride (TPSCl), and were subsequently purified and characterized. The bulky monodentate enantiopure phosphorus(III) 1-phosphanorbornane silyl ethers 6a,b were obtained by desulfurization with excess Raney nickel, and showed better activity and selectivity as ligands in iridium-catalyzed asymmetric hydrogenation.
Article
Green & Sustainable Science & Technology
Shasha Zheng, Zhihong Wei, Bartosz Wozniak, Fabian Kallmeier, Eszter Barath, Haijun Jiao, Sergey Tin, Johannes G. de Vries
Summary: This article introduces a strategy for synthesizing benzenoid aromatics from bio-based feedstock, which shows the potential to replace fossil-based resources in aromatics production.
NATURE SUSTAINABILITY
(2023)
Article
Chemistry, Physical
Shahbaz Ahmad, Ellis Crawford, Muhammad Bilal, Johannes G. de Vries, Michael Buhl
Summary: The detailed mechanism for ruthenium-catalysed selective reduction of cardanol derivatives by transfer hydrogenation has been fully characterised at the B3PW91-D3/ECP2/PCM//B3PW91/ECP1 level of density functional theory. The catalytic cycle involves the hydrogenation of the triene cardanol giving the diene product via a highly stable eta(3)-allylic intermediate. The further reduction to the cardanol monoene product required elevated temperatures and had a high overall barrier, explaining the observed selectivity towards the monoene product.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Kyzgaldak Ramazanova, Soumyadeep Chakrabortty, Bernd H. Mueller, Peter Loennecke, Johannes G. de Vries, Evamarie Hey-Hawkins
Summary: A convenient synthesis method for enantiopure mixed donor phosphine-phosphite ligands has been developed, incorporating P-stereogenic phosphanorbornane and axially chiral bisnaphthols into one ligand structure. These ligands exhibited excellent selectivity and moderate enantioselectivity in various catalyzed reactions.
