Article
Chemistry, Multidisciplinary
Sebastian Mummel, Felix Lederle, Eike G. Huebner, Jan C. Namyslo, Martin Nieger, Andreas Schmidt
Summary: Sydnone methides are rare compounds that can form pi-electron rich anionic N-heterocyclic carbenes and coordinate with various metals, while also undergoing C-C coupling reactions under specific catalysts. Studies have determined their electronic properties and NMR spectra.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Qi Chen, Qing Liu, Jie Xiao, Xuebing Leng, Liang Deng
Summary: This paper presents a catalytic method for the preparation of deuterated NHCs, using a coordinatively unsaturated Ru NHC catalyst to achieve selective deuterium labeling. Mechanistic studies revealed the high regio-selectivity of this catalytic system, offering a new approach for the synthesis of deuterated NHCs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Benon P. Maliszewski, Tahani A. C. A. Bayrakdar, Perrine Lambert, Lama Hamdouna, Xavier Trivelli, Luigi Cavallo, Albert Poater, Marek Belis, Olivier Lafon, Kristof Van Hecke, Dominic Ormerod, Catherine S. J. Cazin, Fady Nahra, Steven P. Nolan
Summary: In this study, the catalytic activity of a series of platinum(II) pre-catalysts with N-heterocyclic carbene (NHC) ligands in the alkene hydrosilylation reaction is reported. The structural and electronic properties of these catalysts are fully characterized using X-ray diffraction analysis and nuclear magnetic resonance spectroscopy (NMR). A structure-activity relationship within this group of pre-catalysts is established, and mechanistic insights into the catalyst activation step are provided. One of the complexes shows exceptional catalytic performance, achieving a turnover number (TON) of 970,000 and a turnover frequency (TOF) of 40,417 h(-1) at 1 ppm catalyst loading. Furthermore, a solvent-free and open-to-air alkene hydrosilylation protocol with efficient platinum removal (reducing residual Pt from 582 ppm to 5.8 ppm) is disclosed.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Cesar Ruiz-Zambrana, Ana Gutierrez-Blanco, Sergio Gonell, Macarena Poyatos, Eduardo Peris
Summary: Two NDI-functionalized complexes of rhodium and iridium were prepared using NDI bis-imidazolium salts as N-heterocyclic carbene precursors. Reduction of the complexes resulted in enhanced electron-richness of the metal and increased catalytic activity in cycloisomerization reactions of alkynoic acids. Two-electron reduction of the ligand further enhanced the catalytic activity, demonstrating the catalyst's ability to switch between three redox species with distinct catalytic activities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Nanoscience & Nanotechnology
Zichao Wei, Kayceety Mullaj, Aleisha Price, Kecheng Wei, Qiang Luo, Srinivas Thanneeru, Shouheng Sun, Jie He
Summary: This study presents a method for preparing metal nanoparticles (NPs) using polymer N-heterocyclic carbenes (NHCs) as surface ligands. The results demonstrate that polymer NHC-modified AgNPs exhibit excellent resistance to oxidative etching and enhanced peroxidase activity.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Pradeep K. R. Panyam, Boshra Atwi, Felix Ziegler, Wolfgang Frey, Michal Nowakowski, Matthias Bauer, Michael R. Buchmeiser
Summary: Rh(I) NHC and Rh(III) Cp* NHC complexes were immobilized inside mesoporous SBA-15, showing different reactivity and selectivity, particularly for aliphatic alkynes. The immobilized catalysts in SBA-15 exhibited excellent selectivity in hydrosilylation reactions, attributed to the confinement effect generated during immobilization.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Multidisciplinary
Sara Kopf, Florian Bourriquen, Wu Li, Helfried Neumann, Kathrin Junge, Matthias Beller
Summary: Organic compounds labeled with hydrogen isotopes are crucial in drug discovery and development in the pharmaceutical industry. Recent advancements have been made in methodologies for isotopic enrichment of organic molecules, including hydrogen isotope exchange reactions, isotopically labeled analogues of organic reagents, and other transformations with isotope incorporation.
Article
Chemistry, Multidisciplinary
Arne Merschel, Dennis Rottschaefer, Beate Neumann, Hans-Georg Stammler, Mark Ringenberg, Maurice Van Gastel, T. Ilgin Demirer, Diego M. M. Andrada, Rajendra S. S. Ghadwal
Summary: In this study, we have successfully synthesized and isolated two stable anions K[SIPrBp] (4 a-K) and K[IPrBp] (4 b-K). These anions, derived from classical N-heterocyclic carbenes (NHCs), exist as violet crystalline solids.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Bastiaan Kooij, Zhaowen Dong, Paul Varava, Farzaneh Fadaei-Tirani, Rosario Scopelliti, Laura Piveteau, Kay Severin
Summary: This study reports the preparation and structural characterization of vanadium complexes with N-heterocyclic vinylidene ligands, enabled by utilizing diazoolefins as ligand precursors. Structural and theoretical analysis show that N-heterocyclic vinylidenes can act as strong 6e(-) donor ligands, forming strong metal-carbon interactions.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Runxia Nan, Yiwen Li, Zhouli Zhu, Fan Qi, Xu-Qiong Xiao
Summary: This study focused on the synthesis and transformation of functional groups in metallacarboranes, and investigated their impact on the structure and properties of the metallacarborane framework.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Yunquan Man, Shiwen Liu, Bo Xu, Xiaojun Zeng
Summary: A method of N-fluorocarboxamide-directed N-heterocyclic-carbene (NHC)-catalyzed benzylic C-H acylation with aldehydes via the hydrogen atom transfer strategy is disclosed. This method involves a sequence of single-electron transfer, 1,5-hydrogen atom transfer, and radical cross-coupling steps, providing facile access to various highly functionalized ketones with good chemical yields and functional group tolerance.
Article
Chemistry, Organic
Devenderan Ramanathan, Qinglong Shi, Meichen Xu, Rui Chang, Beatriz Penin, Ignacio Funes-Ardoiz, Juntao Ye
Summary: We report a photochemical approach for the asymmetric deuterosilylation of exocyclic olefins using mannose-derived thiols as the chiral catalyst and inexpensive deuterium oxide as the deuterium source. DFT computational studies show that multiple non-covalent interactions between the thiol catalyst and the radical adduct are responsible for controlling the enantioselectivity of the reaction.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis has the potential to achieve oxidative and oxygenative transformations, generating various NHC-bound intermediates and enabling non-umpolung processes through the activation of carbon atoms and heteroatoms. This review aims to discuss the recent developments in the field of oxidative NHC catalysis since 2014, with a focus on pivotal intermediates and their mechanistic involvement. More details can be found in the review article by C. De Risi and co-workers.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis enables oxidative and oxygenative transformations, producing various NHC-bound intermediates and facilitating non-umpolung processes by activating carbon atoms and heteroatoms. This review discusses the developments in the literature on oxidative NHC catalysis since 2014, with a specific focus on pivotal intermediates and their mechanistic involvement.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Iris Berg, Einav Amit, Lillian Hale, F. Dean Toste, Elad Gross
Summary: In this study, a N-heterocyclic carbene (NHC) nanolayer was successfully anchored on the surface of a copper electrode using an electrochemical method, resulting in improved oxidation resistance of copper.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Inorganic & Nuclear
Raquel Puerta-Oteo, Ana Ojeda-Amador, M. Victoria Jimenez, Jesus J. Perez-Torrente
Summary: This article highlights recent developments on the application of transition metal-based zwitterionic complexes in catalysis, including selected zwitterionic catalysts in polymerization reactions and advances in hydrogenation/dehydrogenation reactions related to energy applications.
DALTON TRANSACTIONS
(2022)
Article
Polymer Science
Marta Angoy, M. Victoria Jimenez, Fernando J. Lahoz, Eugenio Vispe, Jesus J. Perez-Torrente
Summary: A series of neutral and cationic rhodium complexes with NHC ligands functionalized with different substituents have been prepared and shown to efficiently catalyze the polymerization of phenylacetylene. The catalytic activity of these complexes is influenced by the type of NHC ligand functionalization, with complexes bearing flexible amino-alkyl wingtips showing higher activity. Studies reveal the presence of branched polymers in samples obtained with certain catalysts, indicating the involvement of neutral alkynyl species in the polymerization process.
Article
Chemistry, Multidisciplinary
Maria Galiana-Cameo, Raul Romeo, Asier Urriolabeitia, Vincenzo Passarelli, Jesus J. Perez-Torrente, Victor Polo, Ricardo Castarlenas
Summary: The dinuclear complex [Rh(eta-C1)(eta(2)-coe)(IPr)](2) serves as an efficient catalyst for the O-selective Markovnikov-type addition of 2-pyridones to terminal alkynes. DFT calculations suggest a hydride-free pathway involving intramolecular oxidative protonation of a pi-alkyne by a kappa N-1-hydroxypyridine ligand. The release of the alkenyl ether is considered the rate-determining step in the reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Miguel Gonzalez-Lainez, M. Victoria Jimenez, Ramon Azpiroz, Vincenzo Passarelli, F. Javier Modrego, Jesus J. Perez-Torrente
Summary: This study evaluates a set of neutral and cationic Ir(I) compounds as catalyst precursors for the N-methylation of aniline using methanol. The results show that the compounds with NHC and -OMe ligands can selectively transform aromatic and heterocyclic amines into N-methylamino derivatives with high selectivity under low catalyst loading and substoichiometric amounts of base. Mechanistic investigations suggest the involvement of Ir(I) intermediates and the methoxo complex as the catalytic active species.
Article
Materials Science, Multidisciplinary
Ramon Azpiroz, Marina Borraz, Aida Gonzalez, Catalina Mansilla, Manuel Iglesias, Jesus J. Perez-Torrente
Summary: A porous TiO2 coating with good photocatalytic activity was prepared on glass using the ALD/MLD method.
Article
Chemistry, Multidisciplinary
M. Pilar del Rio, B. Eva Villarroya, Jose A. Lopez, Ana M. M. Geer, Fernando J. J. Lahoz, Miguel A. A. Ciriano, Cristina Tejel
Summary: This study describes the synthesis of neutral and dicationic tetrametallic iridium chains connected by an iridium-iridium bond. The complexes exhibit fractional averaged oxidation states and electronic delocalization along the metallic chain. The absorption spectra of the complexes show characteristic bands that can be fine-tuned by varying the terminal capping ligands.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Polymer Science
Pablo Hermosilla, Daniel Funes-Hernando, Ricardo Castarlenas, Andrea Di Giuseppe, Ramon Azpiroz, Eugenio Vispe, Jesus J. Perez-Torrente
Summary: The catalytic system of [Rh(mu-Cl)(IPr)(eta 2-coe)]2/pyridine efficiently facilitates the polyhydrothiolation reaction between dithiols and dialkynes, resulting in the formation of sulfur-rich poly(vinylidene sulfide)s with high molecular weights and high vinylidene sulfide content. The combination of different types of dithiols and dialkynes allows the preparation of poly(vinylidene sulfide)s with varying properties.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Romane Manguin, Maria Galiana-Cameo, Tanakorn Kittikool, Cecile Barthes, Jompol Thongpaen, Etienne Bancal, Sonia Mallet-Ladeira, Sirilata Yotphan, Ricardo Castarlenas, Marc Mauduit, Jean-Baptiste Sortais, Olivier Basle
Summary: This article discusses the synthesis and characterization of a new series of iridium complexes with NHC-carboxylate ligands, which exhibit efficient catalytic activities in dehydrogenative directed C-H silylation of arenes, with excellent ortho-selectivity control.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Ana Luque-Gomez, Pilar Garcia-Orduna, Fernando J. Lahoz, Manuel Iglesias
Summary: A new method for preparing Co(I)-NHC complexes has been developed, which involves the direct reaction of imidazolium salts with Co(0) complex. The obtained complexes have shown efficient catalytic activity in the reductive amination of furfural and levulinic acid, using silanes as reducing agents. The side reaction of hydrosilylation process, dehydrocoupling of the silane, has also been observed.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Miguel Gonzalez-Lainez, M. Victoria Jimenez, Vincenzo Passarelli, Jesus J. Perez-Torrente
Summary: Neutral and cationic cyclooctadiene rhodium(i) complexes with a lutidine-derived polydentate ligand have been synthesized and found to efficiently catalyze the hydrosilylation of 1-hexyne with high selectivity. These catalysts exhibit a different β-(Z) selectivity compared to previously reported rhodium(i) catalysts based on 2-picolyl-functionalized NHC ligands. Kinetic studies suggest an energy barrier of 19.8±2.0 kcal mol(-1) for the hydrosilylation reaction.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Roberta Colaiezzi, Chiara Saviozzi, Nicola di Nicola, Stefano Zacchini, Guido Pampaloni, Marcello Crucianelli, Fabio Marchetti, Andrea Di Giuseppe, Lorenzo Biancalana
Summary: The reductive N-monomethylation of nitroarenes can be conveniently realized in one-pot using methanol as the reductant, methylating agent, and solvent. New ruthenium(II) arene complexes were developed as efficient catalytic precursors for the tandem reduction/N-methylation of aromatic nitrocompounds with methanol, starting from commercially available and inexpensive dioxime ligands.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Inorganic & Nuclear
Marco Palmese, Jesus J. Perez-Torrente, Vincenzo Passarelli
Summary: This study investigates the reaction mechanism and structures of the iridium(III) derivatives produced from the reactions of [IrCl(cod)(SiNP)] and [Ir{kappa C-3,P,P '-(SiNP-H)}(cod)] with various oxidants. The reactions include allyl chloride and tert-butyl isocyanide, as well as [FeCp2]X, I-2, and CF3SO3CH3. The crystal structures of selected compounds confirm the products of these reactions.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Marco Palmese, Jesus J. Perez-Torrente, Vincenzo Passarelli
Summary: In this study, the iridium(I)-aminophosphane complex [Ir{kappa C-3,P,P'-(SiNP-H)}(cod)] was prepared by reaction of [IrCl(cod)(SiNP)] with KCH3COO. It was found that this reaction proceeds through an unexpected outer sphere mechanism. Various iridium(III) derivatives were obtained by reacting [IrCl(cod)(SiNP)] or [Ir{kappa C-3,P,P'-(SiNP-H)}(cod)] with different oxidants. The crystal structures of selected compounds were determined.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Sophie Beard, Alejandro Grasa, Fernando Viguri, Ricardo Rodriguez, Jose A. Lopez, Fernando J. Lahoz, Pilar Garcia-Orduna, Pilar Lamata, Daniel Carmona
Summary: This article presents transition metal frustrated Lewis pair compounds and their activation of bonds in small molecules, discussing their mechanisms and catalytic properties.
DALTON TRANSACTIONS
(2023)