Article
Chemistry, Medicinal
Nadja Kampschulte, Tim Berking, Ibrahim E. Celik, Stefan F. Kirsch, Nils Helge Schebb
Summary: In this study, the structure-activity relationship of the inhibition of fatty acid-oxidizing cytochrome P450 monooxygenase by flavonoids was investigated. A potent and selective compound, 4'-trifluoromethylflavone, was identified as an inhibitor of 20-HETE formation.
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Chemistry, Organic
Min-Qi Hu, Ying Zhang, Kai-Li Dai, Li-Fang Yu, Ting Liu, Jie Tang, Fan Yang
Summary: A convenient method for constructing 3-(2-methoxypyridin-3-yl)-4H-chromen-4-ones has been successfully developed, with high yields and good functional group compatibility. Further derivatization was achieved through Suzuki-Miyaura cross-coupling reaction, potentially opening up new possibilities for exploring the biological activity of these compounds.
Article
Chemistry, Multidisciplinary
Philipp Zimmermann, Deniz Ar, Marie Roessler, Patrick Holze, Beatrice Cula, Christian Herwig, Christian Limberg
Summary: The synthesized Ni complexes, stabilized by Lewis-acidic cations, show a decreasing trend in CO2 activation within the Li, Na, and K series. The K+ ion has a significant impact on the stability and behavior of the Ni-CO22- entity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Kranthi Kumar Gangu, J. V. S. K. Vasantha Kalyani, T. Satya Guru, Suresh Maddila, Sreekantha B. Jonnalagadda
Summary: The preparation of a new ternary nanocomposite (Ti/FAp/MWCNTs) consisting of titania, fluorapatite, and multiwalled carbon nanotubes, demonstrates excellent catalytic efficiency for synthesizing new pyrazolo [3,4-b] quinolones with impressive yields (91-95%). The nanocomposite also exhibits recyclability (>5 times).
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Chemistry, Analytical
Abeer M. E. Hassan, Tamer Awad Ali, Gehad G. Mohamed, Fakher M. Ahmed, Adel Ehab Ibrahim, Sami El Deeb, Baher I. Salman, Hany A. Batakoushy
Summary: A novel modified carbon paste electrode using Epoxide natural rubber as a chemical modifier was developed for quantifying mercuric ions in water samples. The electrode exhibited a Nerstian response in wide detection ranges, with low limits of detection. It demonstrated excellent stability and selectivity for mercury ions, and was successfully applied in real-world petroleum water samples. The use of Epoxide natural rubber enhances the environmental friendliness of the analytical method.
MICROCHEMICAL JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Alisa S. Sunagatullina, Ferdinand H. Lutter, Paul Knochel
Summary: In this study, various dialkylmagnesiums were synthesized by reacting primary or secondary alkyl iodides with sBu(2)Mg, and these reagents underwent diverse reactions with different compounds to yield stereodefined products. Mechanistic studies revealed that these reactions proceed via a radical pathway.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Alexander Kremsmair, Andreas Hess, Benjamin Heinz, Paul Knochel
Summary: Mixed TMP-bases are excellent reagents for the metalation of functionalized aromatics and heterocycles. By combining with Lewis acids, the metalation scope can be increased, and regioselectivity switches can be achieved. Highly reactive lithium bases are also compatible with various Lewis acids, and performing metalations in continuous flow using commercial setups allows for practical and convenient reaction conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
A. Hess, H. C. Guelen, N. Alandini, A. Mourati, Y. C. Guersoy, P. Knochel
Summary: This study presents a novel method for the selective ortho, ortho'-functionalization of readily available aryl oxazolines using sBu(2)Mg in toluene followed by trapping reactions with electrophiles. The conversions of these nitriles to valuable heterocycles are reported, and a tentative mechanism is proposed for the reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Benjamin Heinz, Dimitrije Djukanovic, Fiona Siemens, Mohamed Idriess, Benjamin Martin, Paul Knochel
Summary: The treatment of 3-halopyridines with certain R-substituents in specific positions using specific reagents under specific conditions provided regioselectively synthesized a series of aminated pyridine compounds with high yields. These substitution reactions may proceed via pyridyne intermediates.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Dimitrije Djukanovic, Maximilian A. Ganiek, Kohei Nishi, Konstantin Karaghiosoff, Kazushi Mashima, Paul Knochel
Summary: A new convenient method for the preparation of dicarbamoylzincs is reported in this study. The target compounds were obtained by reacting ZnCl2 and formamides or TMP2Zn with formamides. This method is compatible with sensitive functional groups such as esters, ketones, or nitro groups. The reaction of these dicarbamoylzincs with various functionalized allylic, benzylic, aryl, alkenyl compounds, acid chlorides, aldehydes, or enones resulted in the synthesis of polyfunctional amides in high yields. The C-13 NMR characterization of these new compounds is presented.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Andreas Hess, Nurtalya Alandini, Yusuf C. Guersoy, Paul Knochel
Summary: A new and storable magnesium amide was prepared and found to be suitable for the non-cryogenic magnesiation of fluoro-substituted arenes and heteroarenes. Further reactions produced a range of polyfunctional fluoro-substituted unsaturated building blocks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Johannes H. Harenberg, Rajasekar Reddy Annapureddy, Konstantin Karaghiosoff, Paul Knochel
Summary: This study reports a lateral sodiation reaction for alkyl(hetero)arenes using a hexane-soluble sodium compound generated on demand, in the presence of TMEDA. The reaction can be conducted under batch and continuous flow conditions. The resulting benzylic sodium species can react with various electrophiles. This method has great potential for synthetic applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Saroj Kumar Rout, Agonist Kastrati, Harish Jangra, Kuno Schwaerzer, Alisa S. Sunagatullina, Maximilien Garny, Fabio Lima, Cara E. Brocklehurst, Konstantin Karaghiosoff, Hendrik Zipse, Paul Knochel
Summary: DFT calculations can predict the reactivity of uncommon N-heterocyclic scaffolds and facilitate their functionalization. Experimental results show that specific catalysts and reagents can achieve the regioselective derivatization of these compounds.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Alexander Kremsmair, Henrik R. R. Wilke, Johannes H. H. Harenberg, Benjamin R. G. Bissinger, Matthias M. M. Simon, Nurtalya Alandini, Paul Knochel
Summary: This study reports a practical in situ quench procedure for the generation of chiral secondary alkyl lithiums from secondary alkyl iodides. The reaction can be carried out in the presence of various electrophiles, resulting in the preparation of a wide range of optically enriched organic compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Petra Regina Varga, Konstantin Karaghiosoff, Eva Viktoria Sari, Andras Simon, Laszlo Hegedus, Laszlo Drahos, Gyorgy Keglevich
Summary: Diethyl alpha-benzylamino- and alpha-amino-benzylphosphonates obtained by the Kabachnik-Fields reaction were useful intermediates in the synthesis of other derivatives. Acylation of alpha-aminophosphonates with acyl chlorides led to the corresponding N-acyl species existing under a dynamic equilibrium of two conformers. NMR measurements at different temperatures revealed hindered rotation in some derivatives.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Alisa S. Sunagatullina, Andreas Hess, Alexander Kremsmair, Yifan Li, Yi-Hung Chen, Paul Knochel
Summary: We present a novel electrophilic amination method for primary, secondary, and tertiary alkyl, benzylic, and allylic zinc and magnesium organometallics using O-2,4,6-trimethylbenzoyl hydroxylamines (O-TBHAs) with yields ranging from 52-99%. These O-TBHAs exhibit excellent long-term stability and can be conveniently synthesized from various highly functionalized secondary amines through a three-step procedure. The amination reactions demonstrate remarkable chemoselectivity without the need for transition-metal catalysts, and are typically completed within 1-3 hours at 25 degrees Celsius. Furthermore, this electrophilic amination process enables the synthesis of enantioenriched tertiary amines (up to 88% ee) using optically enriched secondary alkylmagnesium reagents of the type s-AlkylMgCH(2)SiMe(3).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Konstantin Karaghiosoff, Thomas M. Klapoetke, Maurus B. R. Voelkl
Summary: The advantages of microflow reactors, such as excellent cooling ability, allow for safe exothermic reactions. However, transitioning from small to industrial scale production remains a challenge. A reactor setup has been developed to overcome this limitation and enable the use of highly corrosive materials. As proven by the successful synthesis of nitroguanidine on a lab scale, the new setup improves safety and production rate, making industrial scale-up feasible.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Multidisciplinary
Clemence Hamze, Julie Brossier, Konstantin Karaghiosoff, Edouard Godineau, Paul Knochel
Summary: A regioselective tri- and tetra-functionalization of the pyridazine scaffold was achieved using two readily available building blocks, resulting in the synthesis of a range of pyridazine derivatives.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Agonist Kastrati, Alexander Kremsmair, Alisa S. Sunagatullina, Vasilii Korotenko, Yusuf C. Guersoy, Saroj K. Rout, Fabio Lima, Cara E. Brocklehurst, Konstantin Karaghiosoff, Hendrik Zipse, Paul Knochel
Summary: Straightforward calculations have led to the development of a set of organometallic reactions for the regioselective functionalization of the underexplored fused N-heterocycle imidazo[1,2-a]pyrazine. These reactions provide a way to access polyfunctionalized imidazopyrazine heterocycles.
