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
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, Multidisciplinary
Josep Mas-Rosello, Christopher J. Cope, Eric Tan, Benjamin Pinson, Alan Robinson, Tomas Smejkal, Nicolai Cramer
Summary: Cyclometalated cyclopentadienyl iridium(III) complexes are efficient catalysts in the hydrogenation of oximes, with alkoxy-substituted aryl ketimine ligands providing the best catalytic performance. The stable iridium C,N-chelation is crucial for the catalytic activity, and the hydrogenation system demonstrates high functional group compatibility.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Laurynas Gausas, Bjarke S. Donslund, Steffan K. Kristensen, Troels Skrydstrup
Summary: Polyurethane (PU) is a commonly used thermoset plastic with complex structure, leading to challenges in recycling. The study shows that catalytic hydrogenation of PU materials using a manganese catalyst can effectively deconstruct PU into original monomer components for efficient recovery.
Review
Chemistry, Multidisciplinary
Raphael Gauthier, Jean-Francois Paquin
Summary: This review explores recent advances in the hydrofluorination of diverse alkynes through various activation methods, from classical coinage metal catalysis to metal-free conditions. The method efficiently synthesizes monofluoroalkenes or difluoroalkanes, both of which have applications in medicinal chemistry and beyond. The range of alkynes covered includes unactivated alkynes as well as activated ones such as ynones and derivatives, ynamides, alkynyl sulfides and sulfones, and haloalkynes. Regio- and stereoselective methods exist, but there is still room for improvement depending on the type of alkyne.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Niklas F. Both, Anke Spannenberg, Haijun Jiao, Kathrin Junge, Matthias Beller
Summary: The use of bis(NHC) manganese(I) complexes 3 as catalysts for the hydrogenation of esters was investigated. Various aromatic and aliphatic esters were successfully hydrogenated at mild temperatures and low catalyst loadings using complexes 3 with KHBEt3 as additive, highlighting the efficiency of the novel catalytic system. Additionally, the versatility of the developed catalytic system was demonstrated by the hydrogenation of other substrate classes like ketones, nitriles, N-heteroarenes, and alkenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(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, Physical
Zhao-Ying Yang, Heng Luo, Ming Zhang, Xiao-Chen Wang
Summary: A novel method for the catalyzed hydroboration/hydrogenation cascade reduction of pyridines has been developed, particularly effective for 2,3-disubstituted pyridines, yielding piperidines with high cis selectivity. Mechanistic studies showed that the pyridine substrates and piperidine products acted as bases in cooperation with B(C6F5)(3) to split H-2. This method demonstrated broad functional group tolerance and applicability for the synthesis of biologically active molecules.
Article
Chemistry, Multidisciplinary
Jing Wang, Wenji Wang, Xiongyu Yang, Jingwen Liu, Haizhou Huang, Mingxin Chang
Summary: In this study, a practical homogeneous direct reductive amination (DRA) procedure using iridium catalysis was reported. The reaction conditions were mild and additive-free, allowing for the formation of structurally and functionally diverse amine products, including drugs and compounds from late-stage manipulation. DFT studies revealed that the reaction proceeds via an outer-sphere H-addition pathway with important roles played by pi-pi interactions and H-bonding.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Physical
Tamara Jurado-Vazquez, Efren Rosaldo, Alma Arevalo, Juventino J. Garcia
Summary: This paper reports a homogeneous copper-based catalyst that can catalyze the hydrogenation reaction of levulinic acid under mild reaction conditions, with high yield and selectivity.
Article
Chemistry, Multidisciplinary
Miquel Navarro, Markus Holzapfel, Jesus Campos
Summary: A cavity-shaped gold(I) complex derived from a bulky tri-(ortho-biaryl)-phosphine ligand exhibits preferred selectivity towards terminal functionalities in the gold(I)-catalysed hydration of alkynes under mild heating, thanks to a well-defined pocket as the catalytic active site. This selectivity differs from other gold(I) complexes with bulky phosphine ligands, which show reduced selectivity or similar behavior towards both internal and terminal alkynes. We also explore the potential of gold(III) derivatives for the same catalytic process.
Article
Chemistry, Multidisciplinary
Yuqin Zheng, Taixing Tan, Cheng Wang
Summary: Ag@Ag-Pd-x core-shell nanocomposites with optimized Ag/Pd ratio deposited on Ag nanoplates using a seed growth method show high catalytic performance for semi-hydrogenation of phenylacetylene and other alkynes containing functional groups under mild conditions. Alloying and ensemble effects are responsible for the observed catalytic activity.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Xiaohua Hou, Xiaojian Chen, Xiang Gao, Lei Xu, Hui Zou, Li Zhou, Zong-Quan Wu
Summary: The binuclear vanadium alkylidene showed higher activity in ROMP of norbornene, leading to the formation of cyclic polymers. The size of the polymer ring could be adjusted by the vanadium catalyst structure and polymerization temperature. Similar results were also observed in the ROMP of cyclopentene.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Physical
Andrey N. Pravdivtsev, Arne Brahms, Stephan Kienitz, Frank D. Soennichsen, Jan-Bernd Hoevener, Rainer Herges
Summary: The study found that in the process of hydrogenation and hyperpolarization using parahydrogen (pH(2)) induced polarization (PHIP) in biochemical applications, multiple vinyl ester groups lead to rapid decomposition and the generation of side reactions.
Review
Environmental Sciences
Trinath Biswal, Krushna Prasad Shadangi, Prakash Kumar Sarangi, Rajesh K. Srivastava
Summary: This review provides an explanation of the various methods for converting carbon dioxide (CO2) to methanol, including the use of homogeneous and heterogeneous catalysts, as well as hydrogenation, photochemical, electrochemical, and photoelectrochemical techniques. The article emphasizes the importance of proper catalyst selection and method development to break the stable CO2 bond and produce valuable chemicals like methanol.
Review
Chemistry, Analytical
Mark D. Straub, John Arnold, Julianna Fessenden, Jaqueline L. Kiplinger
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Jade Fostvedt, Michael A. Boreen, Robert G. Bergman, John Arnold
Summary: This study demonstrates the formation of a diverse array of organic and organometallic products containing newly formed C-C bonds via successive methyl transfers from di-, tri-, and tetramethyl Ta(V) precursors to unsaturated small molecule substrates. The reactions of Ta(V) methyl complexes with CO led to the formation of oxo enolate Ta(V) products and imido enamine Ta(V) products. Surprisingly, a new dianionic scorpionate ligand was formed through a reaction involving methyl transfer from the metal center. Mechanistic studies revealed a new reaction pathway in early transition metal chemistry.
INORGANIC CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Erik T. Ouellette, Julian S. Magdalenski, Robert G. Bergman, John Arnold
Summary: Low-valent transition metalates are highly reactive chemical reagents that find applications in organic synthesis, small-molecule activation, transient species stabilization, and M-E bond formation. Recent studies have discovered new types of highly reactive metalates without traditional carbonyl ligands. These metalates display unique reactivity in small-molecule activation, metal-metal bond formation, and heterometallic complex synthesis.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Inorganic & Nuclear
Anukta Jain, Jade Fostvedt, Benjamin M. Kriegel, David W. Small, Lauren N. Grant, Robert G. Bergman, John Arnold
Summary: In this study, the reactivity between a beta-diketiminate-supported niobium(III) imido complex and alkyl azides was demonstrated, resulting in the formation of niobatetrazene complexes. The reaction mechanism was also determined using computational methods.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Michael A. Boreen, Christopher Z. Ye, Andrew Kerridge, Karl N. McCabe, Brighton A. Skeel, Laurent Maron, John Arnold
Summary: This study investigates the mechanism of isomerization of uranium complexes. Experimental and computational studies reveal two different intramolecular C-H activation mechanisms involved.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Erik T. Ouellette, Julian S. Magdalenski, Robert G. Bergman, John Arnold
Summary: We report the synthesis and characterization of a novel rhenium-group 9 heterobimetallic diazenido species and its related diazenido and hydride complexes. Furthermore, we demonstrate the possibility of N-C bond formation in heterobimetallic complexes and investigate their properties using spectroscopy and computational studies.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Christopher Z. Ye, Iker Del Rosal, Michael A. Boreen, Erik T. Ouellette, Dominic R. Russo, Laurent Maron, John Arnold, Clement Camp
Summary: Reaction of potassium pentamethylcyclopentadienyl iridate tris-hydride with UCl4 and ThCl4 led to the generation of multimetallic complexes with different hydride bonding modes. Computational studies suggest that the bonding between U/Th and Ir is significant and involving f-orbitals. The variation in hydride bonding is attributed to differences in dispersion effects.
Review
Chemistry, Multidisciplinary
Gabriela I. Vargas-Zuniga, Michael A. Boreen, Daniel N. Mangel, John Arnold, Jonathan L. Sessler
Summary: The diverse coordination modes and electronic features of actinide complexes of porphyrins and related oligopyrrolic systems have been the subject of interest since the 1960s. Most work has focused on thorium and uranium, but the ligand environments provided by porphyrinoids have led to the stabilization of unique complexes with early actinides. This review summarizes key examples of prophyrinoid actinide complexes, with emphasis on synthesis, structure, electronic features, and reactivity patterns of representative systems.
CHEMICAL SOCIETY REVIEWS
(2022)
Article
Chemistry, Inorganic & Nuclear
Erik T. Ouellette, Ambre Carpentier, I. Joseph Brackbill, Trevor D. Lohrey, Iskander Douair, Laurent Maron, Robert G. Bergman, John Arnold
Summary: Salt metathesis reactions between a low-valent rhenium(I) complex and a series of amidinate-supported tetrylenes led to the formation of rhenium metallotetrylenes with varying extents of Re-E multiple bonding. Temperature played a crucial role in the reactions, leading to isolation of unusual products under different conditions, reflecting the complexity of these metal complexes. Bonding interactions within these complexes were discussed through various spectroscopic, structural, and computational investigations.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Jade Fostvedt, Lauren N. Grant, Benjamin M. Kriegel, Andreas H. Obenhuber, Trevor D. Lohrey, Robert G. Bergman, John Arnold
Article
Chemistry, Inorganic & Nuclear
Michael A. Boreen, Oliver A. Gross, Stephan Hohloch, John Arnold
DALTON TRANSACTIONS
(2020)
Article
Chemistry, Inorganic & Nuclear
Michael A. Boreen, Colin A. Gould, Corwin H. Booth, Stephan Hohloch, John Arnold
DALTON TRANSACTIONS
(2020)
Article
Chemistry, Multidisciplinary
Liane M. Moreau, Alexandre Herve, Mark D. Straub, Dominic R. Russo, Rebecca J. Abergel, Selim Alayoglu, John Arnold, Augustin Braun, Gauthier J-P Deblonde, Yangdongling Liu, Trevor D. Lohrey, Daniel T. Olive, Yusen Qiao, Julian A. Rees, David K. Shuh, Simon J. Teat, Corwin H. Booth, Stefan G. Minasian
Article
Chemistry, Multidisciplinary
Michael A. Boreen, Guodong Rao, David G. Villarreal, Fabian A. Watt, R. David Britt, Stephan Hohloch, John Arnold
CHEMICAL COMMUNICATIONS
(2020)
Article
Chemistry, Multidisciplinary
Trevor D. Lohrey, Jade Fostvedt, Robert G. Bergman, John Arnold
CHEMICAL COMMUNICATIONS
(2020)
