Article
Chemistry, Multidisciplinary
Francis Bru, Mathieu Lesieur, Albert Poater, Alexandra M. Z. Slawin, Luigi Cavallo, Catherine S. J. Cazin
Summary: The synthesis and isolation of [Pd(NHC)(PhC equivalent to CPh)] complexes were reported, which are new 14-electron Pd(0)-complexes that serve as key synthons for known palladium(0) and palladium(II) species and allow access to unprecedented mixed NHC-phosphite palladium(0) complexes. These complexes are also capable of catalyzing the facile hydrosilylation of allenes. DFT calculations provided insights into the relatively weak interaction between the metal and the diphenylacetylene ligand, comparing it with other ligands with varying coordinating power, structure, and electronic properties.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Ying Wang, Zi-Lu Wang, Wei-Wei Ma, Yun-He Xu
Summary: A copper-catalyzed regioselective Markovnikov 3,4-hydrosilylation of 2-substituted 1,3-dienes has been successfully achieved. A wide range of 2-substituted 1,3-dienes and trihydrosilanes are compatible under the optimal conditions. The use of a bisphosphine ligand with a rigid backbone provides the Markovnikov 3,4-hydrosilylation product with better yield and selectivity. Additionally, the synthetic utilities of the allylsilanes were demonstrated through their flexible derivatizations.
Review
Chemistry, Multidisciplinary
Johannes Grosskopf, Thorsten Bach
Summary: Upon irradiation with a suitable chiral catalyst, racemic compounds can be converted into enantiopure compounds through a process called photochemical deracemization. This review comprehensively covers the research and current developments in this field, discussing the reactions and mechanistic details underlying the presented reaction. Photochemical deracemization offers a unique opportunity to directly obtain enantiopure compounds from racemates, and short-lived intermediates play a key role in determining the enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Akira Saito, Shinya Adachi, Naoya Kumagai, Masakatsu Shibasaki
Summary: The strategic use of a sterically demanding Ni-II pincer carbene complex has enabled high enantioselectivity in the direct catalytic asymmetric addition of acetonitrile to aldehydes, resulting in highly enantioenriched beta-hydroxynitriles. This highly atom-economical process offers a promising pathway for utilizing inexpensive acetonitrile as a C2 building block in practical synthetic toolbox for asymmetric catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Peng Zhang, Qi Xu, Xiao-Mei Wang, Jia Feng, Chuan-Jun Lu, Yingzi Li, Ren-Rong Liu
Summary: The first enantioselective synthesis of N-N bisindole atropisomers via palladium-catalyzed construction of one indole skeleton is reported in this study. A wide variety of N-N axially chiral bisindoles were generated with good yields and excellent enantioselectivities through a cascade condensation/N-arylation reaction. The reaction mechanism and enantiocontrol were further investigated using density functional theory (DFT) calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Jiaxin Han, Larry Hoteite, Joseph P. A. Harrity
Summary: The first enantioselective Pd-catalyzed asymmetric allylic alkylation of alpha-fluoro-beta-ketoesters has been achieved with up to 92% ee using Trost family chiral ligands. This work provides new insights into the modest selectivities associated with acyclic alpha-fluoroenolates and experimental evidence that poor levels of enantiocontrol in these systems are not necessarily due to E/Z enolate mixtures. Additionally, this methodology enables the easy preparation of useful 3-fluoropiperidine intermediates, demonstrating applicability to a variety of functionalization reactions for the discovery of bioactive products.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Cassandre C. Bories, Marion Barbazanges, Etienne Derat, Marc Petit
Summary: This study describes the use of silyl cobalt (III) dihydride complexes as catalysts for hydrosilylation reactions, which are efficient for a variety of imines with different protecting groups, as well as aliphatic ketimines and quinoline. Kinetic, DFT calculations, NMR spectroscopy, deuteration experiments, and X-ray diffraction analyses were used to propose a catalytic cycle based on silyl dihydrocobalt (III) complexes performing hydrocobaltation.
Article
Chemistry, Multidisciplinary
Hiroto Uno, Koki Kawai, Taichi Araki, Motoo Shiro, Norio Shibata
Summary: Gem-difluoromethylene moieties are attractive in medicinal chemistry due to their ability to mimic other more ubiquitous functional groups. A novel asymmetric method for their construction was developed, allowing easy access to chiral 1,3-dioxanes that contain a tetrasubstituted difluoroalkyl stereogenic center. The gem-difluoro substitution pattern promotes the reaction, and various substrates were suitable for this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Jiajun Wu, Satawat Tongdee, Yuvaraj Ammaiyappan, Christophe Darcel
Summary: By starting from nitroarenes and using hydrosilylation conditions with a well-defined N-heterocyclic carbene iron(0) catalyst, aniline derivatives were successfully produced in moderate to high yields. Furthermore, a selective synthesis of cyclic amines such as pyrrolidines, piperidines, and azepanes was achieved from levulinic acid, 1,5- and 1,6-keto acids, respectively, with isolated yields up to 69% under visible light irradiation and thermal conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Susannah A. A. Miller, Damien Guironnet
Summary: Functionalizing inorganic particles with organic ligands is a common technique for heterogenizing organometallic catalysts. We studied the unexpected latency in catalytic activity of molecular platinum coordinated to silica nanoparticles functionalized with norbornene ligands. We found that this latency is related to ligand density, chemical structure of the norbornene, and nanoparticle topology. Additionally, we demonstrated the benefit of this latency for triggering curing of silicone elastomers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Jia-Jun Jiang, Man-Kin Wong
Summary: This review summarizes the rapid development of asymmetric gold catalysis in the past ten years, focusing on newly developed gold-catalyzed enantioselective organic transformations and recent progress in ligand design since 2016, organized according to different types of chiral ligands for asymmetric gold(I) and gold(III) catalysis.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
James E. Baumann, Gojko Lalic
Summary: A new method for the differential dihydrofunctionalization of terminal alkynes has been developed, enabling the synthesis of allylic boronate esters through a reductive three-component coupling reaction. This transformation, promoted by a copper/palladium catalyst system, hydrofunctionalizes both pi-bonds of the alkyne. The method is compatible with a wide range of functional groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Simon Sieger, Ilja Lubins, Bernhard Breit
Summary: A highly versatile palladium-catalyzed allylation reaction has been reported, providing a waste-free access to allylated nucleophiles with unlimited possibilities for further functionalization. The reaction can be conducted using propadiene in toluene, and the mechanism is supported by deuterium labeling experiments.
Article
Chemistry, Physical
Simon V. Sieger, Ilja Lubins, Bernhard Breit
Summary: A highly versatile palladium-catalyzed allylation reaction using various pronucleophiles has been reported. Through the use of propadiene in toluene, this reaction provides an efficient and waste-free method to obtain allylated nucleophiles with unlimited potential for further functionalization. The Pd/BINAP system is not only capable of adding N-, O-, and S-pronucleophiles, but also C-pronucleophiles to allene. The plausible mechanism is supported by deuterium labeling experiments.
Review
Chemistry, Multidisciplinary
Chuan-Jun Lu, Qi Xu, Jia Feng, Ren-Rong Liu
Summary: In the past few decades, the Buchwald-Hartwig reaction has played a vital role in the pharmaceuticals, materials, and catalysis fields as a powerful tool for forming C-N bonds. However, the development of asymmetric Buchwald-Hartwig amination reactions for constructing centered chirality, planar chirality, and axial chirality has been limited due to substrate scope and ligand design challenges. Recent interest in the synthesis of C-N/N-N atropisomers has led to a resurgence in asymmetric Buchwald-Hartwig amination chemistry, providing a practical protocol for the preparation of C-N atropisomers. This review discusses reported protocols and their chemical practicality.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Shuxin Mao, Svenja Budweg, Anke Spannenberg, Xiaodong Wen, Yong Yang, Yong-Wang Li, Kathrin Junge, Matthias Beller
Summary: The combination of Fe(OTf)(2) with N-methyl bis(picolylamine) (Me-bpa) L7 enables the epoxidation of linear olefins, including terminal, internal, and cyclic ones, using hydrogen peroxide as a terminal oxidant under mild conditions. Improved yields of epoxides up to 75% have been achieved in the presence of picolinic acid as an additive.
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
Fabio G. Delolo, Johannes Fessler, Helfried Neumann, Kathrin Junge, Eduardo N. Dos Santos, Elena Gusevskaya, Matthias Beller
Summary: A phosphine-oxide-promoted, cobalt-catalysed reductive etherification using syngas as a reductant has been reported in this study. This novel methodology has been successfully applied to prepare unsymmetrical ethers from a wide range of aldehydes and alcohols containing diverse functional groups, and the reaction has been scaled-up to multigram scale under relatively mild conditions. Mechanistic experiments suggest an acetalization-hydrogenation sequence.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
David K. Leonard, Pavel Ryabchuk, Muhammad Anwar, Sarim Dastgir, Kathrin Junge, Matthias Beller
Summary: In this study, a nickel-based catalyst supported on titania is used as a safe alternative to expensive and potentially dangerous catalysts for hydrodehalogenation reactions. The catalyst is prepared by depositing nickel(II)/1,10-phenanthroline on titania and subsequent pyrolysis. It is found that this nanostructured catalyst is efficient for the selective hydrodehalogenation of various substrates. The practicality of this catalyst system is demonstrated by successfully dehalogenating environmentally hazardous and polyhalogenated substrates.
Article
Chemistry, Multidisciplinary
Wu Li, Jabor Rabeah, Florian Bourriquen, Dali Yang, Carsten Kreyenschulte, Nils Rockstroh, Henrik Lund, Stephan Bartling, Annette-Enrica Surkus, Kathrin Junge, Angelika Brueckner, Aiwen Lei, Matthias Beller
Summary: Isotope labelling, especially deuteration, is an important tool for drug development, allowing for identification and quantification of metabolites. This study demonstrates a scalable and efficient method for selective deuteration using a nanostructured iron catalyst.
Article
Chemistry, Multidisciplinary
Florian Bourriquen, Nils Rockstroh, Stephan Bartling, Kathrin Junge, Matthias Beller
Summary: A new class of heterogeneous catalysts is reported in this study for deuterium incorporation in anilines, phenols, and heterocyclic substrates. The optimal material can be conveniently synthesized and allows for high deuterium incorporation using deuterium oxide as the isotope source. This new catalyst has been fully characterized and successfully applied to label natural products and marketed drugs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Nanoscience & Nanotechnology
Shuxin Mao, Pavel Ryabchuk, Sarim Dastgir, Muhammad Anwar, Kathrin Junge, Matthias Beller
Summary: In this paper, a heterogeneous intermetallic nickel silicide catalyst was developed by impregnating nickel acetate/1,10-phenanthroline on fumed silica and subsequent pyrolysis. The optimized catalyst displayed good activity and selectivity for hydrogenation of N-heterocycles, including pyridines and quinolines, under mild conditions using water as the solvent. Notably, it is the first efficient nickel-based heterogeneous catalyst reported for catalytic pyridine hydrogenation.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Peter McNeice, Marc-Andre Mueller, Jonathan Medlock, Werner Bonrath, Nils Rockstroh, Stephan Bartling, Henrik Lund, Kathrin Junge, Matthias Beller
Summary: A lead- and palladium-free alternative to the Lindlar catalyst has been developed for semi-hydrogenation of alkynes. The catalyst, silica-supported nickel nanoparticles modified by nitrogen-doped carbon, shows high selectivity even in the presence of easily reducible groups, making it attractive for various synthetic applications.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Veronica Papa, Johannes Fessler, Francesco Zaccaria, Julien Hervochon, Phong Dam, Christoph Kubis, Anke Spannenberg, Zhihong Wei, Haijun Jiao, Cristiano Zuccaccia, Alceo Macchioni, Kathrin Junge, Matthias Beller
Summary: In this study, several imidazolylphosphine pincer ligands and corresponding Mn complexes were synthesized, characterized, and studied in depth using experimental and theoretical investigations. The complexes showed good to excellent performance in various hydrogenation reactions, particularly in the reduction of N-heterocycles. Spectroscopic studies provided evidence for a classical metal-ligand cooperative mechanism and identified amido and hydrido species.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Physical
Duo Wei, Xinzhe Shi, Ruiyang Qu, Kathrin Junge, Henrik Junge, Matthias Beller
Summary: Chemical hydrogen storage and release processes are crucial for new energy vectors, involving catalysts for efficient and stable operation. This review focuses on the current state of using heterogeneous materials as catalysts for chemical hydrogen storage and release systems. The advantages and disadvantages of these systems compared to homogeneous catalysts are discussed.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Physical
Fabio G. Delolo, Johannes Fessler, Helfried Neumann, Kathrin Junge, Eduardo N. dos Santos, Elena V. Gusevskaya, Matthias Beller
Summary: Phosphine oxides, particularly tricyclohexylphosphine oxide (P7), have been found to promote the cobalt catalyzed carbonylative ring expansion and reductive ring opening reaction of oxetanes under syngas atmosphere. The yields of the desired products, gamma-lactones or primary alcohols, can be controlled by the substrate structure and the stability of the carbocation intermediate. The presence of syngas is crucial for the catalyst activity and stability, and green solvents such as dimethyl carbonate (DMC) can replace traditional solvents for a more sustainable process.
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Haifeng Qi, Shuxin Mao, Jabor Rabeah, Ruiyang Qu, Na Yang, Zupeng Chen, Florian Bourriquen, Ji Yang, Jianfeng Li, Kathrin Junge, Matthias Beller
Summary: In this study, a new catalyst has been developed for the selective cleavage of thermodynamically stable C-C/C=C bonds in the presence of air and water. Mechanistic studies have revealed the importance of water and identified two species generated from O-2 and H2O that are involved in the cleavage reaction. This catalytic system shows broad applicability and high activity, selectivity, and durability.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Physical
Duo Wei, Xinzhe Shi, Ruiyang Qu, Kathrin Junge, Henrik Junge, Matthias Beller
Summary: Chemical hydrogen storage and release processes are crucial for the implementation of new energy vectors. The use of heterogeneous catalytic systems for this purpose is practical and can be easily applied on an industrial scale.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Peter McNeice, Marc-Andre Mueller, Jonathan Medlock, Werner Bonrath, Nils Rockstroh, Stephan Bartling, Henrik Lund, Kathrin Junge, Matthias Beller
Summary: Researchers have achieved the synthesis of vitamin precursors using a lead- and palladium-free catalyst. The catalyst, made of cobalt nanoparticles supported on silica modified by nitrogen doped carbon, allows the production of various fine chemicals and vitamin precursors. It can be conveniently recycled and used multiple times with consistent activity, selectively hydrogenating alkynes in the presence of easily reducible functional groups, making it a versatile catalyst for synthetic organic chemistry.
Article
Chemistry, Multidisciplinary
Florian Bourriquen, Julien Hervochon, Ruiyang Qu, Stephan Bartling, Nils Rockstroh, Kathrin Junge, Cedric Fischmeister, Matthias Beller
Summary: A convenient and practical diastereoselective cis-hydrogenation method for multi-substituted pyridines and arenes was reported. The use of a novel heterogeneous ruthenium catalyst resulted in high yields (typically >80%) of corresponding piperidines and cyclohexanes with good functional group tolerance under mild conditions. The robust ruthenium supported catalyst can be easily prepared and reused multiple times without loss of activity.
CHEMICAL COMMUNICATIONS
(2022)
