Article
Chemistry, Multidisciplinary
Louis Le Moigne, Tommaso Posenato, David Gajan, Jennifer Lesage de la Haye, Jean Raynaud, Emmanuel Lacote
Summary: Amine-borane dimers and oligomers were synthesized via capping agent-controlled polycondensation, and they exhibited excellent catalytic performance in transfer hydrogenation reactions. The oligomers with amine-borane Lewis pairs and congested bis(amine-borane) showed the highest yields. Solid-state NMR characterization revealed that the boron-containing materials obtained from transfer dehydrogenation were similar to those obtained from thermal dehydrogenation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Inorganic & Nuclear
Corentin Magnoux, David P. Mills
Summary: In this article, we provide an overview of metallocene anions and their derivatives, [M(Cp(R))(2)](-), where the metal centers exhibit formally +I oxidation states. We focus on d-block examples, from their origins as unstable intermediates in low temperature electrochemical studies to more recent examples of isolated complexes.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nicola L. Oldroyd, Saurabh S. Chitnis, Etienne A. LaPierre, Vincent T. Annibale, Henry T. G. Walsgrove, Derek P. Gates, Ian Manners
Summary: The reactions of N-heterocyclic carbenes with polyaminoborane were studied, and the depolymerization process was found to be catalytic. The products of the reaction varied depending on the type of carbene used.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Juan Pablo Martinez, Bartosz Trzaskowski
Summary: The investigation of stabilizing elusive monomeric species containing multiple boron-chalcogen bonds has led to the preparation of a series of neutral chalcogenboranes using a specific ligand. The bonding properties of these compounds were evaluated using a pi-backdonation model, revealing enhanced bonding properties for certain ligand variations. The analysis is expected to contribute to the optimization of existing ligands and the development of new boron chemistry.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Siripurapu Mounika, Valle Krishnaveni, Marilyn Esclance Dmello, Suresh Babu Kalidindi
Summary: In recent years, amine boranes, particularly ammonia borane, have been under the spotlight as potential candidates for on-board hydrogen storage. Chemists have been working on developing effective catalysts for hydrogen release from ammonia borane, leading to the discovery of new and interesting chemistry of ammonia borane. This has expanded the potential applications of ammonia borane beyond hydrogen storage, such as in nanoparticle synthesis, transfer hydrogenation, and organic synthesis.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Samantha Lau, Danila Gasperini, Ruth L. Webster
Summary: This review discusses the use of H3N.BH3 and its analogues as sacrificial hydrogen donors in transfer hydrogenation reactions, distinguishing between classical TH, nonclassical TH, and hydrogenation pathways. Experimental and computational analyses can be employed to verify or discount mechanisms, displaying how the operating pathway can be disrupted by various factors, leading to nontrivial assignment of the mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Anna E. Koziol, Adam Wlodarczyk
Summary: This study examines several strategies for the development of the synthesis of P-chiral organophosphorus compounds with (L)-prolinol as a source of chirality, and found that the resulting oxazaphospholidines show high effectiveness as ligands in transition metal asymmetric catalysis.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Jan-Erik Siewert, Andre Schumann, Christian Hering-Junghans
Summary: In this study, the selective synthesis of different diaryl diphosphanes and diphosphenes in reductive coupling reactions using PEt3 as a catalyst was demonstrated. The results show the wide applicability of this method in the synthesis of phosphorus compounds. Control experiments revealed a potential oxidation product in the catalytic cycle that could be debrominated by Zn dust as a sacrificial reductant.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Physical
Derya Ozhava, Sibel Duman
Summary: In this study, the in-situ synthesis of four different metal(0) nanoparticles (Pd, Cu, Ru, and Ni) loaded on cellulose (MNPs@Cellulose) and their catalytic activity in the solventless dimethylamine-borane dehydrogenation were investigated. The optimal metal loading percentages and cellulose amounts were determined, and the Arrhenius activation energies were calculated for each metal nanoparticles.
Article
Chemistry, Physical
Maxime Boudjelel, Omar Sadek, Sonia Mallet-Ladeira, Yago Garcia-Rodeja, E. Daiann Sosa Carrizo, Karinne Miqueu, Ghenwa Bouhadir, Didier Bourissou
Summary: In this work, Pd complexes derived from ambiphilic ligands were found to preferentially activate acyl chlorides over other functional groups, enabling efficient catalysis in Stille and Negishi couplings. This provides a simple and effective method to selectively form C(=O)-C bonds and access functionalized ketones. Key Pd complexes have been authenticated and reaction profiles analyzed using density functional theory (DFT) calculations to gain insight into their role and influence in the process.
Article
Chemistry, Applied
P. Veeraraghavan Ramachandran, Henry J. Hamann, Randy Lin, Aman Singh
Summary: In this study, a novel method for the synthesis of amineborane adducts using in situ generated, transient sodium monohydroxyborohydride in ethyl acetate was reported. The synthesis of heteroaromatic pyridine-, 2-picoline-, and 5-ethyl-2-methylpyridine-boranes was successfully demonstrated at 100 mmol scale, as well as pyridineborane at 1.1 mole scale. The substitution of ethyl acetate for tetrahydrofuran as the solvent allows for the activation of sodium borohydride by the aqueous portion of the dual-solvent system, making this green protocol more economically feasible for large-scale production of amine-boranes, as quantitatively demonstrated by the computed green chemistry metrics.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Multidisciplinary
Hua-Zhen Duan, Cheng Hu, Yue-Lin Li, Shi-Hao Wang, Yan Xia, Xiaohong Liu, Jiangyun Wang, Yong-Xiang Chen
Summary: This study presents a method to genetically incorporate borane-protected phosphine into proteins, followed by a straightforward one-pot strategy for deboronation and palladium coordination. The genetically encoded phosphine ligand P3BF is expected to greatly expand our ability to design functional metalloproteins.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Jianwen Liu, Wenzhi Luo, Yaru Yin, Xian-Zhu Fu, Jing-Li Luo
Summary: By studying the stepwise dissociative C-H bond activation, the mechanism of non-oxidative dehydrogenation of propane is elucidated. Frontier orbital analysis indicates that a smaller gap between HOMO and LUMO results in higher reaction activity. Modulating the gap between the HOMO of propane and the LUMO of catalysts is shown to be a critical strategy for the design of catalysts for non-oxidative propane dehydrogenation.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Organic
Robin Sievers, Joshua Parche, Nico G. Kub, Moritz Malischewski
Summary: This review discusses the distinct changes in properties of metal complexes that occur with the incorporation of fluorinated substituents in cyclopentadienyl anions, such as electrochemical properties or metal-ligand bonding energies. The synthetic challenges of preparing and coordinating fluorinated cyclopentadienyl anions are summarized in this article.
Article
Chemistry, Applied
Vinita Yadav, Ekambaram Balaraman, Santosh B. Mhaske
Summary: This study reports an air-stable, molecularly defined NNN-Mn(II) pincer complex catalyzing acceptorless dehydrogenative coupling of alcohols with indoles, successfully synthesizing various bis(indolyl)methane derivatives and important structurally relevant products. Mechanistic studies highlight the significance of the NH moiety in the complex and the crucial role of metal-ligand cooperation during catalysis.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Inorganic & Nuclear
Yu-Ying Kuo, Rosenildo C. Da Costa, Hazel A. Sparkes, Mairi F. Haddow, Gareth R. Owen
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Merian Crumbach, Jonas Bachmann, Lars Fritze, Andreas Helbig, Ivo Krummenacher, Holger Braunschweig, Holger Helten
Summary: Access to dithiophene-fused oxadiborepins and the first azadiborepins via a modular synthesis route has been achieved. These new compounds emit intense blue light, some demonstrating fluorescence quantum yields close to unity. The weak aromatic character of the novel 1,2,7-azadiborepin ring was demonstrated through in-depth theoretical investigations using nucleus-independent chemical shift (NICS) scans and anisotropy of the induced current density (ACID) calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Nicolas Alexander Riensch, Lukas Swoboda, Artur Lik, Ivo Krummenacher, Holger Braunschweig, Holger Helten
Summary: A series of methylene-bridged bis(triarylboranes) were successfully synthesized using metal-free catalytic Si/B exchange condensation under mild conditions. These compounds exhibit effective internal pi-conjugation, but the conjugation between the two borane units is disrupted by the aliphatic linker. Cyclic voltammetry and UV-vis spectra further revealed the electronic structure properties of the compounds.
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
(2021)
Article
Chemistry, Multidisciplinary
Fabian Schorr, Nils Schopper, Nicolas Riensch, Felipe Fantuzzi, Marco Neder, Rian D. Dewhurst, Torsten Thiess, Tobias Brueckner, Kai Hammond, Holger Helten, Maik Finze, Holger Braunschweig
Summary: Novel alkynyl-functionalized diarylbis(dimethylamino)diboranes(4) were prepared by salt metathesis, and their appended alkynyl groups underwent hydroboration to yield discrete boryl-appended diborane(4) species when reacted with monohydroboranes. Conversely, reactions with dihydroboranes led to the formation of oligomeric species with B-B bonds, with some exhibiting good air stability and solubility in common organic solvents. These oligomeric species, characterized by NMR, vibrational spectroscopy, and size-exclusion chromatography, can contain up to ten repeat units.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Polymer Science
Lars Fritze, Maximilian Fest, Andreas Helbig, Tobias Bischof, Ivo Krummenacher, Holger Braunschweig, Maik Finze, Holger Helten
Summary: The doping of alpha-oligofurans with boron leads to the formation of new materials with favorable optoelectronic properties, tunable emission colors in the visible range, and robust optical features. Spectroelectrochemical investigations reveal the reversible reduction of these materials to radical anions and subsequently to dianions, demonstrating their oxidatively stable nature.
Article
Chemistry, Multidisciplinary
Sonja Fuchs, Arumugam Jayaraman, Ivo Krummenacher, Laura Haley, Marta Bastovanovic, Maximilian Fest, Krzysztof Radacki, Holger Helten, Holger Braunschweig
Summary: We found that the outcome of the tin-boron exchange reaction depends on the steric bulk of the aryl substituent of the borane reagent, resulting in the formation of either boroles or large diboracycles. NMR spectroscopic studies showed that the two products can reversibly interconvert in solution, and density functional theory calculations revealed boroles to be intermediates in the formation of the diboracyclic products.
Article
Chemistry, Multidisciplinary
Stephan Hagspiel, Felipe Fantuzzi, Merle Arrowsmith, Annalena Gaertner, Maximilian Fest, Jonas Weiser, Bernd Engels, Holger Helten, Holger Braunschweig
Summary: The reaction of a cyclic alkyl(amino)carbene (CAAC)-stabilized thiazaborolo[5,4-d]thiazaborole (TzbTzb) with strong Bronsted acids results in the protonation of both TzbTzb nitrogen atoms. The coordination of counteranions or solvent molecules to the doubly protonated fused heterocycle via hydrogen-bonding interactions influences the visible and fluorescence colors of these salts. DFT calculations show that the hydrogen bonding affects the charge transfer character, enabling fine-tuning of absorption and emission spectral features.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Matthias Maier, Johannes Chorbacher, Anna Hellinger, Jonas Klopf, Julian Guenther, Holger Helten
Summary: This study focuses on oligo- and poly(arylene iminoborane)s with a backbone of phenylene or thiophene moieties linked via B=N units. The researchers successfully prepared various polymers and oligomers with tailored electronic properties using a modular synthetic approach. The compounds exhibited effective pi-conjugation, solid-state emission, and aggregation-induced emission behavior.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Editorial Material
Chemistry, Inorganic & Nuclear
Holger Helten, Rory Waterman
Summary: This special collection has been created to honor Prof. Streubel on his retirement, showcasing his significant contributions to the field of low-valent phosphorous chemistry, with a central theme on the beauty of inorganic chemistry.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Matthias Maier, Vivien Zeh, Nadine Munker, Julian Glock, Kai Oberdorf, Ozan Ayhan, Crispin Lichtenberg, Holger Helten
Summary: The incorporation of BN units into organic scaffolds by isoelectronic/isosteric substitution has proven effective in producing new materials. However, the knowledge about BN-doped inorganic-organic hybrid polymers is limited, especially for linear or cyclolinear macromolecules with longer inorganic chains. In this study, 1,2,5-azadiborolane was introduced as a novel building block for polymers. By coupling it with a p-phenylene diamine-based co-monomer, a hybrid polymer with a B2N3 chain and a considerable molecular weight was obtained. The UV-vis spectra revealed a red-shift in the longest-wavelength absorption band with increasing number of BN units in the chain.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Johannes S. S. Schneider, Ivo Krummenacher, Holger Braunschweig, Holger Helten
Summary: In this study, various linear oligo(p-phenylene iminoboranes) with pendent ferrocene groups were synthesized from oligo(p-phenylene vinylenes) by BN modification. The formation of the unprecedented macrocycle was achieved through a stoichiometric reaction of bis-silylamine with a bisborane, without the need for a template.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Vivien Zeh, Johannes S. Schneider, Jonas Bachmann, Ivo Krummenacher, Holger Braunschweig, Holger Helten
Summary: This study presents the first poly(ferrocenylene iminoborane), a polyferrocene-based metallopolymer, and a series of monodisperse ferrocenylene iminoborane oligomers, shedding light on the structural and electronic nature of this novel class of hybrid materials.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Matthias Maier, Jonas Klopf, Clemens Glasmacher, Felipe Fantuzzi, Jonas Bachmann, Ozan Ayhan, Abhishek Koner, Bernd Engels, Holger Helten
Summary: In this study, the treatment of N-silyl-B-chloro-aminoborane was investigated. It was found that substoichiometric quantities of Me3SiOTf led to B-N coupling, whereas activation with 5 mol% of Ag[Al{OC(CF3)(3)}(4)] resulted in Cl/Me exchange between the boron and the silicon center. Combined experimental and computational studies supported a chain reaction initiated by nucleation-limited chloride abstraction in the latter process.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Nicolas Alexander Riensch, Maximilian Fest, Lars Fritze, Andreas Helbig, Ivo Krummenacher, Holger Braunschweig, Holger Helten
Summary: A series of bifuran-bridged bis(triarylboranes) have been synthesized via classical metathesis or catalytic silicon/boron exchange reactions. The products are strongly luminescent, with quantum yields up to 85%, and can be reversibly twofold reduced via successive one-electron processes.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Merian Crumbach, Ozan Ayhan, Lars Fritze, Jan A. P. Sprenger, Ludwig Zapf, Maik Finze, Holger Helten
Summary: The synthesis of fully aromatic, luminescent, and highly robust BNB-doped phenalenyls, isoelectronic to the phenalenyl cation, was successfully achieved. B-Fluoromesityl-substitution resulted in fluorescence within a narrow range and a significant increase in reduction potential. Detailed theoretical investigations unveiled an intramolecular aromaticity switch upon one-electron reduction.
CHEMICAL COMMUNICATIONS
(2021)
