Article
Chemistry, Multidisciplinary
Lauren N. Mendelsohn, Ljiljana Pavlovic, Hongyu Zhong, Max R. Friedfeld, Michael Shevlin, Kathrin H. Hopmann, Paul J. Chirik
Summary: The mechanism of asymmetric hydrogenation of prochiral enamides by well-defined cobalt(0) and cobalt(II) precatalysts using a chiral bis(phosphine) ligand has been investigated. Characterization of the resulting complexes and monitoring of the reactions revealed the resting state of the catalyst, the rate law, and the irreversible H2 addition step. Computational and labeling studies provided evidence for a two-electron redox cycling during the catalytic cycle. The experiments support an unsaturated pathway for the hydrogenation of prochiral enamides.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Tianjiao Hu, Lukas Lueckemeier, Constantin Daniliuc, Frank Glorius
Summary: The direct enantioselective hydrogenation of 2-quinolones using Ru(II)-NHC catalyst has been achieved, providing alkyl-, aryl- and halogen-substituted optically active dihydro-2-quinolones in high yields with moderate to excellent enantioselectivities. This reaction presents an efficient and atom-economic pathway to construct simple chiral 3,4-dihydro-2-quinolones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Babulal Maji, Anirban Bhandari, Rayantan Sadhukhan, Joyanta Choudhury
Summary: In this study, water-soluble Ru-NHC complexes were synthesized and tested for their catalytic activity in the transfer hydrogenation of quinoline-type N-heteroarenes using a formic acid/sodium formate buffer solution. The designed ligand within the catalyst backbone exhibited excellent durability, reusability, and compatibility with aqueous-phase operation. The catalytic system demonstrated high efficiency with as little as 0.25 mol% catalyst, providing an overall turnover number of approximately 900.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Organic
Kurt Puntener, Raphael Bigler, Kenta Stier, Marek P. Checinski
Summary: This study investigates the asymmetric hydrogenation of beta-ketoesters catalyzed by [RuCl2(MeOH)(2)((R)-MeOBIPHEP)]. It is found that HCl acts as both an activator and has a significant impact on the reaction. The study also explains the effects of common phosphorus substituents on the activity of the catalyst.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Alexander D. Boeth, Michael J. Sauer, Walter Baratta, Fritz E. Kuehn
Summary: The bis-abnormal N-heterocyclic carbene (aNHC) ruthenium complexes showed high catalytic activity in transfer hydrogenation and Oppenauer-type oxidation reactions. The order of reactivity was found to be influenced by steric effects.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Zhengyu Han, Gang Liu, Xuanliang Yang, Xiu-Qin Dong, Xumu Zhang
Summary: The study developed an efficient and simple synthetic strategy for obtaining both enantiomers of chiral tetrahydroquinoline derivatives through the adjustment of reaction solvents. Gram-scale asymmetric hydrogenation proceeded well with low-catalyst loading, and a possible reaction process was revealed based on various experiments conducted.
Article
Chemistry, Inorganic & Nuclear
Nida Shahid, Rahul Kumar Singh, Navdeep Srivastava, Amrendra K. K. Singh
Summary: A series of Ru(III)-NHC complexes have been prepared through a base-free route. These air and moisture-stable complexes, which represent rare examples of paramagnetic Ru(III)-NHC complexes, were shown to be excellent metal precursors for the synthesis of new Ru(II)-NHC complexes. This work allows easy access to new Ru-NHC complexes for the study of new properties and novel applications.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Lan Mei, Min Du, Yuan Zhang, Cheng Hou
Summary: This study investigates the mechanistic preference of a ruthenium complex with dual proton-responsive sites in borrowing-hydrogen N-alkylation catalysis using DFT calculations. The results suggest that the gamma-NH site facilitates the rate-determining step via non-covalent interaction, while the alpha-NH site requires overcoming a higher activation energy barrier.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Physical
Connor S. MacNeil, Hongyu Zhong, Tyler P. Pabst, Michael Shevlin, Paul J. Chirik
Summary: The cobalt-catalyzed asymmetric hydrogenation of dehydro-sitagliptin was studied and applied to the synthesis of sitagliptin. The discovery of catalysts was accelerated by the synthesis of cationic bis(phosphine) cobalt eta 6-arene complexes. The optimal catalyst showed high yield and enantioselectivity, and maintained excellent activity and selectivity after standing in air for 2 weeks.
Article
Chemistry, Inorganic & Nuclear
Sebastien G. Guillet, Gianmarco Pisano, Soumyadeep Chakrabortty, Bernd H. Mueller, Johannes G. de Vries, Paul C. J. Kamer, Catherine S. J. Cazin, Steven P. Nolan
Summary: An operationally simple and eco-friendly synthetic protocol for [Rh(acac)(CO)(NHC)] complexes is described, with insights into the mechanism provided through operando spectroscopy. The spectroscopic fingerprints of these complexes are correlated to NHCs' electron-donating descriptor values, highlighting a new strategy to evaluate carbenes' electronic properties. An assessment of these complexes in catalytic applications shows promising results in the catalytic hydrogenation of aromatic ketones.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Amrita Gogoi, Priti Singh, Sourav Pal, Mudit Dixit
Summary: In this study, the mechanism and activity changes of Ru-Bis(pyridyl)borate complexes for ammonia borane dehydrogenation were elucidated using density functional theory calculations. The results highlight the importance of ligand hydrogenation in probing the activity and operating mechanism of the catalyst.
INORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Lianpei Zhou, Peipei Ji, Xiuwu Wang, Dongming Qi, Tao Chen
Summary: This study successfully incorporated chiral diamine catalysts into polymeric micelles and formed water-soluble micellar catalysts with chiral diamine ligands. These micellar catalysts were used for asymmetric transfer hydrogenation of ketones in aqueous solutions, showing promising application prospects.
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Tufeil Sartaj Khan, Dheerendra Singh, Pragnya Paramita Samal, Sailaja Krishnamurty, Paresh Laxmikant Dhepe
Summary: This study investigated the kinetic and mechanistic aspects of the catalytic transfer hydrogenation (CTH) strategy for the hydrodeoxygenation (HDO) reaction of oxygenated compounds such as lignin-derived phenolics. By designing catalysts with low metal loading, mild reaction conditions, and high selectivity, high product yields were achieved. Using Ru/Al2O3-acidic catalyst, a 74% cyclohexanol yield from guaiacol was obtained at 225 degrees C, demonstrating the effectiveness of the CTH strategy for industrial applications.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Inorganic & Nuclear
Curtis C. Ho, Angus Olding, Rebecca O. Fuller, Allan J. Canty, Nigel T. Lucas, Alex C. Bissember
Summary: The study reveals that a nickel(I)/(III) cycle is involved in the Suzuki-Miyaura Csp(2)-Csp(2) cross-coupling reaction, with single-electron pathways likely operating in this transformation.
Article
Chemistry, Organic
Dongfeng Yang, Chengyi Wang, Yu Wang, Guohua Liu, Tanyu Cheng, Rui Liu
Summary: A new method for the preparation of enantiomerically pure 1,4-oxazines via asymmetric transfer hydrogenation/cyclization enantio-relay process catalyzed by Ru and Au bimetallic catalysts has been developed. The reaction exhibits high stereoselectivity and enriches the understanding of gold catalysis from a mechanistic perspective.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Guangying Tan, Fritz Paulus, Alessia Petti, Maxim-Aleksa Wiethoff, Anna Lauer, Constantin Daniliuc, Frank Glorius
Summary: A novel radical relay 1,4-carboimination between two distinct olefins with alkyl carboxylic acid-derived bifunctional oxime esters was achieved via energy transfer catalysis. The reaction showed high chemo- and regioselectivity, forming multiple C-C and C-N bonds in a single operation. This mild and metal-free method exhibited a broad substrate scope and excellent tolerance of sensitive functional groups, providing easy access to structurally diverse 1,4-carboiminated products. Furthermore, the obtained imines could be readily converted into valuable biologically relevant free gamma-amino acids.
Article
Chemistry, Medicinal
Tobias Schierling, Beatrice Tosi, Clara Eisenhardt, Sophie Reining, Constantin G. Daniliuc, Christoph Brenker, Timo Struenker, Bernhard Wuensch
Summary: This article introduces a new and more effective inhibitor for studying sperm swimming behavior. The inhibitor is structurally simpler and easier to synthesize compared to existing inhibitors, and shows even better potency. It is envisioned to be widely used in future studies on the physiology of CatSper in sperm.
ACS PHARMACOLOGY & TRANSLATIONAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Yujie Liang, Fritz Paulus, Constantin G. Daniliuc, Frank Glorius
Summary: We report a BF3-catalyzed [2 + 2] cycloaddition reaction between aldehydes and bicyclo[1.1.0]butanes (BCBs) to access polysubstituted 2-oxabicyclo[2.1.1]hexanes. A new BCB containing an acyl pyrazole group was discovered, which not only facilitates the reactions but also allows for diverse downstream transformations. Additionally, aryl and vinyl epoxides can be used as substrates that undergo cycloaddition with BCBs after in situ rearrangement to aldehydes. These results will promote the exploration of complex sp(3)-rich bicyclic frameworks and BCB-based cycloaddition chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Gina Vasile Scaeteanu, Constantin G. Daniliuc, Rodica Olar, Mihaela Badea
Summary: A complex [Zn(bpy)(acr)(2)]center dot H2O was converted into a coordination polymer [Zn(bpy)(acr)(HCOO)](n) in a DMF medium. The polymer was fully characterized through crystallographic analysis, IR, and thermogravimetric analysis. The obtained complex, with its unique composition and structure, is of current interest and rarely reported in the literature.
Article
Nanoscience & Nanotechnology
Florian Bosse, Christian Gutheil, D. Thao Nguyen, Matthias Freitag, Mowpriya Das, Bonnie J. J. Tyler, Thorsten Adolphs, Andreas H. H. Schaefer, Heinrich F. F. Arlinghaus, Frank Glorius, Bart Jan Ravoo
Summary: Planar gold surfaces modified with N-heterocyclic carbene (NHC) were found to be more susceptible to wet chemical etching compared to undecorated areas. The selective decoration of NHCs on gold was achieved by microcontact printing, and the etching behavior could be tuned by changing the concentration of the NHC precursor. Surface patterning was confirmed by time-of-flight secondary-ion mass spectrometry and Kelvin probe force microscopy. The ability to selectively remove gold through surface ligand functionalization enables novel applications of NHCs in materials chemistry and nanofabrication.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Fabian Hoeglsperger, Fayaz Ali Larik, Changzhuang Bai, Maximilian D. Seyfried, Constantin Daniliuc, Henning Klaasen, Pall Thordarson, Jonathon E. Beves, Bart Jan Ravoo
Summary: In this study, water-soluble arylazoisoxazole photoswitches were introduced. The photostationary states and reversible photoisomerization between E- and Z-isomers were observed, indicating their potential for photoresponsive host-guest chemistry in water. Furthermore, hydrogel properties can be manipulated reversibly with light. Overall, arylazoisoxazoles have great potential as molecular photoswitches in aqueous media.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Mowpriya Das, Markus Kohlstaedt, Maria Enders, Stephan Burger, Himadri Sekhar Sasmal, Birger Zimmermann, Andreas Schaefer, Bonnie J. Tyler, Heinrich F. Arlinghaus, Ingo Krossing, Uli Wuerfel, Frank Glorius
Summary: This study demonstrates the modification of ITO surface using N-heterocyclic carbenes (NHCs) precursor, IPr-CO2, via spin coating method. The modified ITO electrodes exhibit significantly reduced work function and provide high electron selectivity contacts in organic photovoltaic devices.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Multidisciplinary Sciences
Jingjing Zhang, Christian Mueck-Lichtenfeld, Armido Studer
Summary: Chemical activation of water is a hot topic in energy research and enables the conversion of this abundant resource into valuable compounds. In this study, we demonstrate the activation of water using a photocatalytic phosphine-mediated radical process, which involves sequential heterolytic and homolytic cleavage of O-H bonds. The resulting PR3-OH radical intermediate can react with various closed-shell p systems, leading to transfer hydrogenation of the p system and incorporation of hydrogen atoms from water into the product. Experimental and theoretical studies support the importance of the hydrogen atom transfer step in this radical hydrogenation process.
Article
Chemistry, Multidisciplinary
Zi-Xuan Wang, Keith Livingstone, Carla Huempel, Constantin G. Daniliuc, Christian Mueck-Lichtenfeld, Ryan Gilmour
Summary: Fluorinated small molecules are commonly used in the field of functional small molecules. Researchers have developed creative approaches to access these important materials by utilizing iodine(I)/iodine(III) catalysis to convert abundant alkene substrates into high-value (di)fluorinated products. They also discovered that enynes can be used as proxies for styrenes, simplifying the process and enabling the generation of highly versatile homopropargylic difluorides.
Article
Chemistry, Organic
Shyam Kumar Banjare, Dirk Leifert, Frauke Weidlich, Constantin G. Daniliuc, Fatmah A. Alasmary, Armido Studer
Summary: An oxidative radical cascade addition cyclization approach using eco-friendly iron catalysis and inexpensive tert-butylhydroperoxide (TBHP) as the oxidant has been reported for the synthesis of quinoline-based p-extended polyheterocyclic compounds. This method utilizes readily available ortho-alkynylated aromatic aldehydes as radical precursors and aryl isonitriles as radical acceptors. By applying this approach, quinolines that are p-conjugated with an additional heteroarene moiety can be prepared in a single sequence using indole and thiophene-based carbaldehydes.
Review
Chemistry, Multidisciplinary
Qiu Sun, Christian Mueck-Lichtenfeld, Gerald Kehr, Gerhard Erker
Summary: The study of 3D architectures at a molecular scale, specifically molecular pyramids with all-carbon frameworks and various geometries, has been a fascinating subject for chemists. While some substituted forms of tetrahedranes and all-carbon [4]-[5]pyramidanes have been experimentally generated and explored, the hypothetical unsubstituted parent [3]-[6]pyramidanes have primarily been studied computationally. However, the replacement of carbon vertices with isolobal main group element fragments has resulted in stable hetero[m]pyramidanes that have been successfully synthesized and characterized.
NATURE REVIEWS CHEMISTRY
(2023)
Article
Chemistry, Physical
Linda Quach, Egy Adhitama, Valentin Goeldner, Ankita Das, Feleke Demelash, Martin Winter, Uwe Karst, Tobias Placke, Frank Glorius
Summary: Film-forming electrolyte additives are crucial for the performance and safety of high-energy-density lithium-ion batteries. This study synthesized derivatives and conducted analyses to investigate the impact of molecular substrate parameters on battery performance. The research aims to enhance the fundamental understanding of influential substrate parameters and guide the design of electrolyte additives for high-energy-density lithium-ion batteries.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Lukas Schifferer, Leon Hoppmann, Robin Groeters, Christian Mueck-Lichtenfeld, Constantin G. Daniliuc, Olga Garcia Mancheno
Summary: A solvent-dependent, divergent synthesis of highly functionalized N,S-heterocycles, containing thiazoline and isoquinuclidine or tetrahydroisoquinoline scaffolds, has been reported. This synthesis involves cyclization reactions of isoquinolinium 1,4-zwitterionic thiolates and shows robustness and applicability as demonstrated by efficient upscaling of the reaction and derivatization of the resulting products.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Tristan Wegner, Alexander Dombovski, Katrin Gesing, Alexander Koehrer, Matthias Elinkmann, Uwe Karst, Frank Glorius, Joachim Jose
Summary: The cell membrane is an important platform for modifying and manipulating cellular behavior. This study presents a method for functionalizing the bacterial membrane using lipid mimetics, allowing for a new type of cascade reaction.
