Article
Chemistry, Multidisciplinary
Tanno A. Schmidt, Stephan Schumann, Andreas Ostertag, Christof Sparr
Summary: In this study, we report the stereoselective synthesis of triptycyl sulfones with atropisomerism using a chiral phosphoric acid catalyst. The oxidation of a stereodynamic thioether controlled by the catalyst allowed selective access to enantioenriched triptycyl sulfoxides. Subsequent enantiospecific and diastereoselective catalytic oxidation resulted in overall control over the stereogenic C-S axis, with a stereoselectivity of up to (-sc): (+sc) : (ap)=94 : 6 :<1.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Applied
Seoung-Mi Choi, Ju Hyun Kim
Summary: This review summarizes the progress made in the synthesis of 2H-pyrroles since 2000, including methods such as dearomatization of 1H-pyrrole, oxidation of pyrrolines or pyrrolidines, ring construction via catalytic cycloaddition, and rearrangement of 3H-pyrroles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Joe Higham, James A. Bull
Summary: Transient directing groups (TDGs) combined with copper have been used for efficient C-H functionalization without additional steps for directing group introduction and removal. This method demonstrates high regioselectivity in the beta-C(sp(2))-H sulfonylation and gamma-(peri)-sulfonylation reactions of benzaldehydes and achieves through the use of catalytic beta-alanine and sulfinate salts, with copper fluoride serving as both the copper source and oxidant.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Thomas R. Puleo, Stephen J. Sujansky, Shawn E. Wright, Jeffrey S. Bandar
Summary: The Concept article discusses recent applications of commercial organic superbases in modern synthetic methodologies, highlighting the advantages of organic superbases in discovering new base-catalyzed reactions, optimizing reactions that require stoichiometric Bronsted base, and in high-throughput experimentation technology.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Organic
Hong Ji, Tingting Li
Summary: Cycl[3.2.2]azine molecules are widely found in both synthetic chemistry and natural products, and have shown promising applications in various research fields. The development of facile and stereoselective methods for the synthesis of cycl[3.2.2]azine derivatives has attracted great interests in recent years. This review systematically summarizes representative achievements in the construction of cycl[3.2.2]azine molecules in both enantioselective and non-asymmetric fashion.
SYNTHETIC COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Wei Zhao, Yanfeng Lv, Ji Li, Zihao Feng, Yonghao Ni, Nikos Hadjichristidis
Summary: Functionalized polypeptides have gained significant interest in various fields due to their tunable physicochemical characteristics, and developing strategies to produce them without metallic contaminants is crucial for applications in high-value and sensitive domains. A highly efficient strategy combining Michael reaction with hydrogen-bonding organocatalytic ROP has been developed to access site-specific functionalized polypeptides with predesigned molecular weights and low polydispersities. This metal-free synthetic process offers high activity and selectivity at room temperature for preparing a library of chain-end and chain-middle functionalized polypeptides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Fengjuan Chen, Luo Liu, Wei Zeng
Summary: Compared with all-carbon parent compounds, incorporating Silicon into carboskeletons gives sila-analogues unique biological activity and physical-chemical properties. Silacycles have shown promising potential in biological chemistry, pharmaceuticals industry, and material chemistry. Therefore, the development of efficient methods to assemble versatile silacycles has been a topic of increasing concern. This review summarizes recent advances in the synthesis of silacycle-system, including transition metal-catalytic and photocatalytic strategies using various starting materials. The mechanistic aspects and features of these reaction methodologies are also highlighted.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hui Zhang, Lihua Song, Weicheng Yuan, Xiaomei Zhang
Summary: A diastereo- and enantioselective aza-Mannich addition of oxazolones to alpha-amino sulfones has been developed using a tertiary amine-1-phenylethyl thiourea catalyzed by a cinchona-based structure. The reaction yielded azlactone adducts with high yields and moderate to excellent stereoselectivity. The absolute configuration of a product was determined by X-ray crystal structural analysis and a plausible reaction mechanism was proposed.
Article
Chemistry, Physical
William Lecroq, Jules Schleinitz, Mallaury Billoue, Anna Perfetto, Annie-Claude Gaumont, Jacques Lalevee, Ilaria Ciofini, Laurence Grimaud, Sami Lakhdar
Summary: An unprecedented combination of light and P(III)/P(V) redox cycling was utilized for efficient deoxygenation of aromatic amine N-oxides. Additionally, it was found that a wide range of aliphatic amine N-oxides could be deoxygenated simply by using phenylsilane. These methods, operating under metal-free conditions, demonstrated good tolerance to various functionalities and high chemoselectivity.
Article
Chemistry, Physical
Ruxu Yao, Youjie Li, Jiahuan Wang, Jinzhu Chen, Yisheng Xu
Summary: This study presents the crown ether-catalyzed reductive functionalization of CO2, leading to the formation of various N-containing benzoheterocyclics and N-formamides. The electron-donating ability of the investigated crown ethers positively correlates with their catalytic activity in CO2 reduction. This work demonstrates the significance of crown ethers as novel organocatalysts for CO2 reduction.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Organic
Min Zheng, Ke Gao, Yanhu Zhang, Hongjian Lu
Summary: An aryl radical in situ SO2-capture reaction was reported for the first time, using aryl diazonium salts as aryl radical precursors and vinyl triflates and allyl(alkynyl) trifluoromethylsulfones as radical acceptors and in situ SO2 donors. The reaction can produce various beta-keto, allyl, and alkynyl arylsulfone derivatives under mild visible-light photoredox-catalytic conditions without requiring external SO2 sources.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Thermodynamics
Ignazio Blanco, Gianluca Cicala, Filippo Samperi, Andrea Scamporrino, Claudio Tosto
Summary: A series of poly(ether sulfone) random copolymers with different loading of diphenolic acid (DPA) units were synthesized and their thermal behavior was comprehensively studied. The copolymers were synthesized from various amounts of 4,4'-dihydroxydiphenylsulfone, DPA, and 4,4'-dichlorodiphenyl sulfone. The degradation activation energy (E-a) was determined and compared with previous studies. The thermal stability evaluation showed good performance, but caution is needed regarding the percentage of pendant carboxylic acid groups, as deterioration of physical properties was observed at 30% content.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Chemistry, Physical
Cristian Rosso, Sara Cuadros, Giorgia Barison, Paolo Costa, Marina Kurbasic, Marcella Bonchio, Maurizio Prato, Luca Dell'Amico, Giacomo Filippini
Summary: We present an efficient photocatalytic method for the direct iodosulfonylation of terminal olefins using alpha-iodo phenylsulfones. The process utilizes a phenol derivative as the precatalytic system and visible-light irradiation. Mechanistic investigations demonstrate the crucial role of the in situ generated phenolate anion in the catalytic process, achieving high yields of up to 95%.
Article
Chemistry, Physical
Yuanyuan Sun, Ying Li, Xiaoyan Li, Yanli Zeng
Summary: In this study, the catalytic mechanism of mono/bis(iodoimidazolium) halogen bond donor catalysts in the Michael addition reaction was investigated. It was found that bis(iodoimidazolium) halogen bond donor catalysts showed good catalytic performance and could accelerate the reaction. The catalyzed reaction involves two steps, with two possible pathways for proton transfer, where the indirect pathway is more likely to occur.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Review
Chemistry, Organic
Barbara C. Lemos, Eclair Venturini Filho, Rodolfo G. Fiorot, Fabrizio Medici, Sandro J. Greco, Maurizio Benaglia
Summary: This MiniReview compiles the most significant successful examples of highly efficient enantioselective catalytic protocols for the Povarov reaction since 2014, and provides a comprehensive discussion of different catalytic strategies employed in recent years. It also critically discusses the controversial dispute regarding the mechanistic pathways of this well-known reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Jonathan Kiehl, Tim Hochdoerffer, Luca M. Carrella, Volker Schuenemann, Mathilde H. Nygaard, Jacob Overgaard, Eva Rentschler
Summary: This study reports on two new complexes that exhibit a wide thermal hysteretic spin crossover effect and a thermally inducible metastable high-spin state at low temperatures. These materials show promise for the development of molecular switches and sensors.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Martin Bargum, Mikkel Krell-Jorgensen, Martin Nielsen, Katrine Qvortrup, Luca Laraia
Summary: This article reports a microfluidic system for photochemical cycloadditions fabricated using silicon micro processing technologies. The optimized system enables the completion of a range of photochemical reactions in just a few minutes using high power UV-LEDs and triplet photosensitizers. The feasibility of performing photochemistry in microflow in an academic research environment is demonstrated, and a reaction leading to a novel scaffold and its mechanistic proposal are reported.
Article
Chemistry, Organic
Danielle L. J. Pinheiro, Martin Nielsen
Summary: The chemoselective reduction of enamides to alpha-amino acids using Ru pincer complexes as catalysts and iPrOH and EtOH as H-donors and solvents is demonstrated. A range of alpha-amino acids is synthesized with good to excellent yields. Applications, large-scale synthesis, and a one-pot experiment are also reported. Deuterium-labeling experiments show high regioselectivity between the alpha- and beta-positions of the alkene unit.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Francesca Franco, Sara Meninno, Jacob Overgaard, Sergio Rossi, Maurizio Benaglia, Alessandra Lattanzi
Summary: An enantioselective synthesis method for functionalized triflones with a quaternary stereocenter has been developed, utilizing the Michael reaction and nucleophilic acyl substitution. The study highlights the potential of the triflinate anion as a leaving group for stereocontrolled postfunctionalizations.
Article
Chemistry, Physical
Rosa Padilla, Zhenwei Ni, Dmytro Mihrin, Rene Wugt Larsen, Martin Nielsen
Summary: In this study, the base-free transfer hydrogenation of biomass derived furanic aldehydes using bio-alcohols as the hydrogen source was investigated using ruthenium and iridium pincer complexes as catalysts. The furanic substrates were successfully converted to the desired alcohols under mild conditions, and the methodology could be extended to different temperatures and deuterium labeling of C-H functions in furanic alcohols was also explored.
Article
Chemistry, Inorganic & Nuclear
Sofie Stampe Leiszner, Khetpakorn Chakarawet, Jeffrey R. Long, Eiji Nishibori, Kunihisa Sugimoto, James A. Platts, Jacob Overgaard
Summary: We conducted an experimental and theoretical study on the metal-metal bonding in the tetranuclear cluster Ni-4((NPBu3)-Bu-t)(4). The results show that the bonding in Ni-4((NPBu3)-Bu-t)(4) is an eight-membered ring structure without direct Ni-Ni bonding. However, calculations reveal the presence of direct Ni-Ni bonding between neighboring Ni atoms. These metal-metal bonding interactions likely contribute to the direct ferromagnetic exchange and the high-spin ground state of the molecule.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Weiguang Jin, Xin Li, Gael Clergeaud, Roslyn M. Ray, Marie Karen Tracy Hong Lin, Thomas Lars Andresen, Charlotte Held Gotfredsen, Martin Nielsen, Kira Astakhova, Katrine Qvortrup
Summary: This study presents a novel strategy that utilizes metalloporphyrin cages to protect and prolong the half-lives of small RNAs (sRNAs). The cage binding also facilitates the internalization of sRNAs, and the released sRNAs maintain their genetic activity in an acidic intracellular environment. Moreover, the photodynamic properties of the cage enable efficient in vitro cell killing in breast cancer treatment.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Luca Piccirilli, Brenda Rabell, Rosa Padilla, Anders Riisager, Shoubhik Das, Martin Nielsen
Summary: High catalytic activities were achieved by using Ru-PNP complexes in ionic liquids for the reversible hydrogenation of CO2 and dehydrogenation of formic acid (FA) under mild conditions without sacrificial additives. The Ru-PNP/IL system showed high conversion rates and space-time yield (STY) for FA, with the potential to be used as a FA/CO2 battery, H2 releaser, and hydrogenative CO2 converter.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Zhenwei Ni, Rosa Padilla, Lucas dos Santos Mello, Martin Nielsen
Summary: In this study, ruthenium PNP pincer complexes were used as catalysts to directly convert ethanol into either primary or secondary alcohols, or hydrocarbons. Phenyl-substituted phosphines led to the selective production of secondary alcohols, while bulky phosphine substituents resulted in the selectivity towards primary alcohols. This methodology shows the potential for selectively producing primary or secondary alcohols and hydrocarbons from bio-alcohols under mild conditions.
Article
Chemistry, Multidisciplinary
Vijay S. Parmar, Andreas M. Thiel, Marie S. Norre, Jacob Overgaard
Summary: The temperature and pressure dependence of a high-performing single molecule magnet, [Dy(Mes*O)(2)(THF)2Br] (1), have been studied. A new polymorph of 1 was observed under pressure and at low temperatures. The distances and energies of the first Kramers doublets remained mostly unchanged, regardless of phase changes and external pressure. The calculated energy barrier to magnetic reversal varied without a clear trend as pressure increased.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Inorganic & Nuclear
Zhenwei Ni, Rosa Padilla, Rajib Pramanick, Mike S. B. Jorgensen, Martin Nielsen
Summary: A base-free, acceptorless dehydrogenative coupling of ethanol to ethyl acetate is achieved using a pincer complex ((PNP)-P-Ph)RuH(BH4)(CO) (0.25 mol%) and m-xylene as the co-solvent. The catalysis shows excellent conversion and yield of >99% after 24 h at 120 degrees C. The scaled-up reaction is also effective under similar conditions.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Sandeep K. Gupta, Hannah H. Nielsen, Andreas M. Thiel, Emil A. . Klahn, Erxi Feng, Huibo B. Cao, Thomas C. Hansen, Eddy Lelievre, Arsen Gukasov, Iurii Kibalin, Sebastian Dechert, Serhiy Demeshko, Jacob Overgaard, Franc Meyer, Franc Meyer
Summary: In this study, a highly anisotropic single-ion magnet (SIM) with stability under ambient conditions was synthesized and comprehensively characterized. The influence of the ligand field on the degeneracy and population of d-orbitals in a specific coordination environment was investigated, providing important insights for the rational design and enhancement of magnetic anisotropy in SIMs.
Article
Chemistry, Multidisciplinary
Vijay S. S. Parmar, Andreas M. M. Thiel, Rizwan Nabi, Gemma K. K. Gransbury, Marie S. S. Norre, Peter Evans, Sophie C. C. Corner, Jonathan M. M. Skelton, Nicholas F. F. Chilton, David P. P. Mills, Jacob Overgaard
Summary: The effects of external pressure on a high-performing dysprosocenium single-molecule magnet were investigated. The effective energy barrier (U-eff) decreased from approximately 1300 cm(-1) at ambient pressure to 1125 cm(-1) at 3 GPa. Results showed that compression below 1.2 GPa had negligible effect on the Orbach process, but magnetic relaxation increased above 1 GPa via Raman relaxation and/or quantum tunnelling of magnetisation.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Medicinal
Eduardo Felipe Alves Fernandes, Jonas Wilbs, Rene Raave, Christian Borch Jacobsen, Hanne Toftelund, Hans Helleberg, Milou Boswinkel, Sandra Heskamp, Magnus Bernt Frederik Gustafsson, Inga Bjornsdottir
Summary: Positron emission tomography (PET) is a non-invasive molecular imaging technique used to visualize the distribution and pharmacology of tracers. This study compared the biodistribution profiles obtained using Zirconium-89 (Zr-89) PET and quantitative whole-body auto-radiography (QWBA) and found consistent profiles during the absorption phase but differences during the elimination phase.
ACS PHARMACOLOGY & TRANSLATIONAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Bryson A. Hawkins, Jonathan J. Du, Felcia Lai, Stephen A. Stanton, Peter A. Williams, Paul W. Groundwater, James A. Platts, Jacob Overgaard, David E. Hibbs
Summary: The study investigates the crystal structure and relative stability of a cocrystal formed by THEO and MA. The results show that the cocrystal does not improve the hygroscopic behavior of THEO and is equally stable as THEO and MA individually. This study highlights the need for further research and balance in cocrystal design.
