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, Physical
Renat Kadyrov
Summary: An efficient and simple catalytic system has been developed for the hydrogenation of carboxylic esters using commercially available Ru-salts and imidazolium salts. This combination enables the reduction of esters to alcohols at moderate temperature and pressure, offering a practical method for alcohol synthesis.
JOURNAL OF CATALYSIS
(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, Multidisciplinary
Ondrej Mozdiak, Jiri Tydlitat, Zdenka Ruzickova, Libor Dostal, Roman Jambor
Summary: In this study, Ru complexes with N-bound 2-pyridonato ligand were prepared and their catalytic activity in base-free transfer-hydrogenation of ketones was investigated.
Article
Chemistry, Physical
Denise Lovison, Tobias Berghausen, Sophie R. Thomas, Jonathan Robson, Markus Drees, Christian Jandl, Alexander Poethig, Patrick Mollik, Dominik P. Halter, Walter Baratta, Angela Casini
Summary: In this study, water-soluble organometallic Ru(II) complexes were synthesized and found to act as anticancer agents by catalyzing transfer hydrogenation reactions with biomolecules. The structure-activity relationship and reaction mechanism were investigated, and the compounds were also tested for their anticancer activity in vitro.
Article
Chemistry, Inorganic & Nuclear
Margarita Ruiz-Castaneda, Lucia Santos, Blanca R. Manzano, Gustavo Espino, Felix A. Jalon
Summary: Deuterium labeling is a process that leads to compounds useful in various fields, with the transfer hydrogenation of aldehydes and selective deuteration of alcohols described in this study. The use of a biphasic water/toluene system was found to enable higher yields and selective D incorporation. Additionally, efficient M-H/D+ exchange from D2O was found to play a key role in the deuteration process.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Daniel J. Tindall, Steffen Mader, Alois Kindler, Frank Rominger, A. Stephen K. Hashmi, Thomas Schaub
Summary: Sugar alcohols are important for the food industry and can be produced in large quantities with increased yield and stereoselectivity through a homogeneous system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Physical
Amit Kumar, Chang Gao
Summary: The increasing production and usage of consumer products and energy sources have led to the accumulation of toxic waste products, posing a severe threat to the planet. The concept of circular chemistry proposes the utilization of waste products as feedstocks for useful chemicals, with catalytic (de)hydrogenation being a green and sustainable approach. Studies on homogeneous catalytic (de)hydrogenation have shown potential to convert chemical wastes into valuable resources, with examples including CO2, N2O, plastics, and glycerol as waste materials for transformation.
Article
Chemistry, Applied
Michelle Jones, Dave Harris, Justin Struble, Michael Hayes, Kevin Koeller, Kathryn Chepiga Oezguen, Heiko Schirmer, Jens Heinrich, Florian Baechle, Sebastien Goudedranche, Christoph Schotes
Summary: This article reports the development activities aimed at creating an efficient process for the large-scale production of a key intermediate for a crabtree/pfaltz-type iridium complex, which is suitable for industrial application. The process involves a highly efficient Suzuki coupling and a highly enantioselective transfer hydrogenation.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Physical
Daniel Timelthaler, Christoph Topf
Summary: This study presents a simple method for the transfer hydrogenation of aromatic aldehydes in i-PrOH using the cost-effective and easy-to-handle [Cr(CO)(6)] as a catalyst. The reactions can be carried out in normal atmosphere without the need for special equipment, and various functional groups are tolerated. Furthermore, the addition of TMAO can further promote the catalytic transformations. This method is also suitable for processing thermo-labile substrates.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Inorganic & Nuclear
Gyorgy Hanko, Richard Marton, Antal Udvardy, Mihaly Purgel, Agnes Katho, Ferenc Joo, Gabor Papp
Summary: The water-soluble cis,mer-[IrH2Cl(mtppms)3] was an effective catalyst for the reduction of terminal alkynes by hydrogen transfer, with the highest rate observed at pH 3. The reactions exclusively yielded corresponding alkenes as products, with excess mtppms ligand inhibiting the reaction by forming a less active complex. The joint mechanism for both hydrogenation and transfer hydrogenation pathways was suggested based on experimental results and DFT calculations.
INORGANICA CHIMICA ACTA
(2021)
Article
Chemistry, Multidisciplinary
Kaili Zhang, Qixing Liu, Renke He, Danyi Chen, Zhangshuang Deng, Nianyu Huang, Haifeng Zhou
Summary: The asymmetric reduction of C = O bonds of 2-arylidene cycloalkanones using a chiral ruthenium complex as a catalyst and HCOOH/Et3N as a hydrogen source resulted in high yields and high enantiomeric excess. This method is not only suitable for small-scale synthesis, but also applicable for the gram-scale synthesis of pharmaceutically important compounds.
Article
Chemistry, Inorganic & Nuclear
Alberto Gobbo, Xinyuan Ma, Gianluca Ciancaleoni, Stefano Zacchini, Lorenzo Biancalana, Massimo Guelfi, Guido Pampaloni, Steven P. Nolan, Fabio Marchetti
Summary: The potential of ruthenium(II) arene complexes in catalytic transfer hydrogenation has been widely investigated, but studies on homologous compounds with tris(1-pyrazolyl)methane (tpm) ligand are lacking. In this study, RuCl(kappa(3)-tpm)(PPh3)(2)]Cl reacted with various nitrogen ligands to form [RuCl(kappa(3)-tpm)(PPh3)(L)]Cl (L=NCMe, NCPh, imidazole) in nearly quantitative yields. These complexes were evaluated as catalytic precursors in the transfer hydrogenation of ketones, and complex 2 exhibited the highest activity.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Jesus Alberto Avendano Villarreal, Fabio Godoy Delolo, Artur Vicari Granato, Elena Vitalievna Gusevskaya, Eduardo Nicolau dos Santos
Summary: Hydroformylation and olefin metathesis are common synthetic tools in the chemical industry. While they have been used in the production of various industrial chemicals within the same synthetic route, there is limited research on combining these two reactions in a one-pot procedure. This study successfully integrated the two reactions and demonstrated efficient synthesis of 2-arylpropanals, valuable compounds for accessing non-steroidal anti-inflammatory drugs.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Energy & Fuels
Yi Chen, Yongsheng Zhang, Wei Lin, Xianglin Cheng, Jianshe Wang, Xiaolong Liu, Chunbao Charles Xu, Renfeng Nie
Summary: In this study, two-dimensional Co-Al hydrotalcite catalysts were successfully fabricated for the conversion of biomass to value-added chemicals under mild conditions. The optimized CoAl-LDO600 catalyst achieved a high yield (94.2%) of octadecanol from oleic acid using iso-propanol as hydrogen donor at 200 degrees C. This catalyst exhibited excellent magnetic separability, stability, and versatility for various fatty acids with alcohol yields ranging from 89.1% to 96.7%.
Article
Chemistry, Multidisciplinary
Paul Zaby, Jan Blasius, Anna K. Mueller, Steven P. Nolan, Oldamur Holloczki
Summary: The formation mechanism of metal-N-heterocyclic carbene (NHC) complexes from imidazolium salts in the presence of weak bases was investigated through theoretical methods. Quantum chemical calculations revealed that both sodium acetate and trimethylamine facilitate complex formation. Molecular dynamics simulations showed that the ionic nature of the [AuCl2](-) and imidazolium ions, as well as the sodium acetate base, keep these species associated in the reaction mixture through ion pairing. The neutral amine, however, remains mostly separated from the other reaction partners, making it a significantly less effective base.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Xinyuan Ma, Manoj V. Mane, Luigi Cavallo, Steven P. Nolan
Summary: An efficient method for the regioselective 1,2-hydrosilylation of N-heteroarenes using silanes as hydride donors is described. The versatile catalyst [RuCl(PPh3)(2)(eta(5)-(3-phenylindenylidene))] is employed for the first time in this catalytic reaction, displaying high efficiency at low loading and mild conditions. The mechanism of this transformation is investigated through stoichiometric reactions and DFT calculations.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Sebastien G. Guillet, Ishfaq Ibni Hashim, Marek Belis, Kristof Van Hecke, Catherine S. J. Cazin, Steven. P. Nolan
Summary: A simple synthetic method for synthesizing various [Rh(acac)(CO)(NHC)] complexes is presented. In situ infrared monitoring provides valuable information on the reaction mechanism, including the identification of a crucial intermediate. Understanding the reaction mechanism has led to the discovery of novel pathways to commonly used congeners.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sebastien G. Guillet, Aleksei A. Logvinov, Vladislav A. Voloshkin, Ekaterina A. Martynova, Steven P. Nolan
Summary: Researchers report a simple method for the synthesis of azetidines from 2-isoxasoline-3-carboxylates and alkenes, using [Au(cbz)(NHC)] complexes as photocatalysts. The reaction is applicable to a wide range of substrates. Mechanistic studies confirm the energy transfer pathway. This study further expands the potential application of gold catalysts in energy transfer chemistry and catalysis.
Article
Chemistry, Physical
David C. Cabanero, Jennifer A. Nguyen, Catherine S. J. Cazin, Steven P. Nolan, Tomislav Rovis
Summary: A system has been developed that uses deep red to near-infrared light to activate a latent ruthenium olefin metathesis catalyst. This is achieved by using an osmium(II) photocatalyst that is excited to its triplet state and a latent solvent-coordinated, cationic precatalyst that undergoes excited-state single-electron reduction. The system demonstrates excellent spatiotemporal control under light irradiation and shows improved light penetration through barriers.
Article
Chemistry, Physical
Nikolaos V. Tzouras, Leandros P. Zorba, Entzy Kaplanai, Nikolaos Tsoureas, David J. Nelson, Steven P. Nolan, Georgios C. Vougioukalakis
Summary: Despite the usefulness of gold catalysis in organic synthesis, it often requires activators and/or additives to generate cationic forms of gold catalysts. In this study, hexafluoroisopropanol (HFIP) is found to be a simple tool for gold-catalyzed cycloisomerizations, eliminating the need for external activators. HFIP acts as both a solvent and an activator through dynamic activation of the Au-Cl bond via hydrogen bonding. This unique mode of catalysis enables efficient and scalable cyclization reactions without the use of complex ligand/catalyst designs or activators.
Article
Chemistry, Physical
Sylwia Ostrowska, Lorenzo Palio, Agnieszka Czapik, Subhrajyoti Bhandary, Marcin Kwit, Kristof Van Hecke, Steven P. Nolan
Summary: In this study, a synthetic protocol was developed to prepare palladacycle complexes using a mild base and environmentally friendly solvent, with a focus on complexes with backbone-substituted N-heterocyclic carbene ligands. The accessible complexes exhibited high catalytic activity in the Buchwald-Hartwig amination, with low catalyst loading and mild reaction conditions achieved in a green solvent.
Article
Chemistry, Organic
Shiyi Yang, Xiang Yu, Yaxu Liu, Michele Tomasini, Lucia Caporaso, Albert Poater, Luigi Cavallo, Catherine S. J. Cazin, Steven P. Nolan, Michal Szostak
Summary: The Suzuki-Miyaura cross-coupling reaction enables the construction of biaryl ketones from inert amide bonds. However, the mechanism of C(acyl)-N bond oxidative addition and catalyst effect in this reaction remain poorly understood. This study investigates the use of [Pd(NHC)(sulfide)Cl-2] catalysts for amide N-C bond activation and presents the reaction development, kinetic studies, and reaction scope. DFT studies were also conducted to gain insight into the mechanism of C(acyl)-N bond oxidative addition and catalyst activation. The results suggest that [Pd(NHC)(sulfide)Cl-2] precatalysts could find application in C(acyl)-X bond activation in organic synthesis and catalysis.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Xinyuan Ma, Steven P. Nolan
Summary: The first-generation ruthenium-indenylidene olefin metathesis complex catalyzes the 1,2-hydrosilylation reaction to produce dihydroquinoline derivatives with high regioselectivity. The complex shows excellent catalytic efficiency when the challenging Ph2SiH2 hydride donor is used. The reaction is efficient with low catalyst loadings and applicable to a wide range of quinoline derivatives and N-heterocycles. A proposed mechanism for this transformation is based on stoichiometric reactions.
Article
Chemistry, Inorganic & Nuclear
Thomas Scattolin, Aleksei A. Logvinov, Nikolaos V. Tzouras, Catherine S. J. Cazin, Steven P. Nolan
Summary: N-heterocyclic carbene (NHC) ligands have evolved from being lab curiosities to important supporting ligands in various fields such as organometallic chemistry, homogeneous catalysis, medicinal chemistry, and materials science.
Article
Chemistry, Inorganic & Nuclear
Sofie M. P. Vanden Broeck, Nikolaos V. V. Tzouras, Marina Saab, Kristof Van Hecke, Busra Dereli, Ida Ritacco, Luigi Cavallo, Georgios C. C. Vougioukalakis, Pierre Braunstein, Steven P. P. Nolan, Andreas A. A. Danopoulos, Catherine S. J. Cazin
Summary: The 4-RN-1,3-Ar-2-imidazolium salt, R = iPr, tBu, Ar = Mes, Dipp, underwent metalation by Au-I at the C2-, C5-, and 4-RN positions, depending on the reactants and conditions used. A rare direct rearrangement of the Au-I aminide to an abnormal imidazol-5-ylidene Au-I complex was also observed, which may involve TfO- facilitated H+ transfer, according to a DFT study.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Sylwia Ostrowska, Pierre Arnaut, David J. Liptrot, Catherine S. J. Cazin, Steven P. Nolan
Summary: The synthesis, isolation, and full characterization of a new copper complex [Cu(IPr)(OC(H)(CF3)(2))] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) are reported. This copper(I) complex is a versatile synthon capable of activating various X-H bonds including C-H, N-H, and S-H bonds. [Cu(IPr)(OC(H)(CF3)(2))] was investigated as a pre-catalyst in several catalytic reactions.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Raphael Gauthier, Nikolaos V. Tzouras, Steven P. Nolan, Jean-Francois Paquin
Summary: The gold-catalyzed hydration of 2,2,2-trifluoroethyl-substituted alkynes exhibits high regioselectivity, resulting in the formation of β-trifluoromethylketones as the major products. This transformation highlights the significant directing effect of the trifluoromethyl group, mediated by its inductive effect, in gold-catalyzed addition to alkynes.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Vladislav A. Voloshkin, Yaxu Liu, Marek Belis, Min Peng, Kristof Van Hecke, Catherine S. J. Cazin, Steven P. Nolan
Summary: The synthesis of novel phosphine palladium PEPPSI and dimer complexes bearing RuPhos, SPhos and XPhos phosphines is reported. The crystal structures of XPhos Pd PEPPSI with pyridine, SPhos Pd PEPPSI with 3-chloropyridine as throw-away ligands and the RuPhos palladium dimer were obtained and compared with previously reported congeners. The catalytic activity of these complexes was examined via a C-N coupling reaction, and it was found that RuPhos complex 2b showed the highest catalytic activity with 97% yield at a low catalyst loading. The addition of 3-pentanone significantly improved the yields of phosphine dimers and PEPPSI complexes when the reactions were performed in THF.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Benon Maliszewski, Eleonora Casillo, Perrine Lambert, Fady Nahra, Catherine Cazin, Steven Nolan
Summary: This article reports an efficient olefin hydrosilylation protocol using Pt(ii)-thioether-based pre-catalysts. These simple and readily available complexes exhibit excellent catalytic performance and offer significant advantages over existing alternatives, enabling rapid and high conversions at ppm-level catalyst loadings.
CHEMICAL COMMUNICATIONS
(2023)
