Article
Chemistry, Multidisciplinary
Peter Wonneberger, Nils Koenig, Menyhart B. Sarosi, Evamarie Hey-Hawkins
Summary: Reduction of 1-phospha-2-azanorbornene derivative leads to formation of a novel compound 1-phosphabicyclo[3.2.1]octa-2,5-diene and an unusual 2H-phosphole dimer. Additionally, 3H-phospholes were found to potentially act as dienophile in the dimerisation reaction under elevated temperatures, contrary to previous assumptions of their synthetic irrelevance.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Rui Chang, Yubing Pang, Juntao Ye
Summary: This study reports a photoinduced approach for hydroarylation of unactivated olefins using 4-hydroxycoumarins as the arylating reagent. The key to the success of this reaction is the conversion of nucleophilic 4-hydroxycoumarins into electrophilic carbon radicals through photocatalytic arene oxidation. This method not only overcomes the polarity-mismatch issue encountered under ionic conditions but also allows for a broad substrate scope and inhibits side reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yi Gong, Cai Wang, Feng Zhou, Kui Liao, Xi-Yu Wang, Ying Sun, Yan-Xue Zhang, Zhi Tu, Xin Wang, Jian Zhou
Summary: This study presents the first highly selective kinetic resolution of racemic alpha-chiral azides through Cu-catalyzed azide-alkyne cycloaddition (CuAAC). Newly developed pyridine-bisoxazoline (PYBOX) ligands bearing a C4 sulfonyl group enabled effective kinetic resolution and asymmetric CuAAC of racemic azides derived from privileged scaffolds such as indanone, cyclopentenone, and oxindole, leading to alpha-tertiary 1,2,3-triazoles with high to excellent ee values. DFT calculations and control experiments revealed that the C4 sulfonyl group decreased the Lewis basicity of the ligand and increased the electrophilicity of the copper center for better recognition of azides, while also functioning as a shielding group to enhance the efficacy of the chiral pocket of the catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tsukasa Tawatari, Ritsuki Kato, Riku Kudo, Kiyosei Takasu, Hiroshi Takikawa
Summary: In this study, we report on the intramolecular (3+2) cycloaddition reactions between ynamides and benzyne. These reactions involve the formation of two bonds and are facilitated by using benzyne precursors containing a chlorosilyl group. The intermediate indolium ylide in these reactions exhibits both nucleophilic and electrophilic properties at its C2 atom.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Shi-Yi Zhuang, Jin-Yi Liu, Hui Guo, Yong-Xing Tang, Xiang-Long Chen, Jin-Tian Ma, Yan-Dong Wu, An-Xin Wu, Kai-Lu Zheng
Summary: A metal-free multicomponent cascade annulation reaction using an I2-DMSO mediator has been developed, which involves trifunctionalization of the substrate and cleavage of bonds to obtain pyrrolo[2,1-a]isoquinoline derivatives with a quaternary carbon center.
Article
Chemistry, Multidisciplinary
Johanna Proessdorf, Christian Jandl, Thomas Pickl, Thorsten Bach
Summary: It was found that while 2-alk-omega-enyloxy-sustituted benzaldehydes do not display any photochemical reactivity at the arene core, the respective iminium perchlorates undergo efficient reactions under certain conditions, leading to products with different molecular structures and stereochemical features.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xinyao Li, Johannes Grosskopf, Christian Jandl, Thorsten Bach
Summary: 3-Substituted quinoxalin-2(1H)-ones and various aryl-substituted or tethered olefins can undergo an enantioselective aza Paterno-Buchi reaction upon irradiation with a chiral sensitizer at lambda=420 nm. The absolute and relative configuration of the products were elucidated by X-ray crystallography, suggesting triplet energy transfer in a hydrogen-bonded complex between the imine substrate and the catalyst. Preliminary experiments also explored intramolecular cycloaddition and alternative reaction modes of quinoxalinones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Li-Jun Wu, Qianru Wang, Jianping Guo, Junnian Wei, Ping Chen, Zhenfeng Xi
Summary: Through the synergy of heterogeneous and homogeneous synthetic approaches, N-containing organic compounds can be synthesized using activated N-containing species prepared from N-2 gas and suitable carbon sources. Li2CN2 was successfully prepared as the activated N-containing species and utilized as a novel synthetic synthon for constructing N-containing organic compounds. Various valuable nitrogen-containing compounds were synthesized in moderate to excellent yields using Li2CN2 under mild conditions, including N-15-labeled products with anti-cancer activity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Samuel Nees, Tim Wellnitz, Fabian Dankert, Marcel Haerterich, Simon Dotzauer, Milica Feldt, Holger Braunschweig, Christian Hering-Junghans
Summary: Heterocycles containing group 13 and 15 elements play important roles in organic, biomedical, and materials chemistry. However, heterocycles containing P and Al elements are rare. In this study, phosphaalumenes were used to react with alkynes, alkenes, and conjugated double bond systems. Different types of heterocycles, including phosphaalumetes, phosphaaluminabarrelenes, and aluminaphosphorinanes, were synthesized. Experimental work, along with theoretical studies, provided insights into the mechanism of these heterocycle formations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Stephan Hagspiel, Felipe Fantuzzi, Rian D. Dewhurst, Annalena Gaertner, Felix Lindl, Anna Lamprecht, Holger Braunschweig
Summary: Lewis base adducts and cyclodimers of the parent boraphosphaketene were prepared for the first time, with one adduct undergoing decarbonylation and phosphinidene insertion to form very rare 1,2-phosphaborinines, B/P isosteres of benzene. The strong donor properties of these 1,2-phosphaborinines were confirmed through synthesis of their pi complexes with Group 6 metals.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sebastien Carret, Benjamin Darses, Soufiane Touil, Jean-Francois Poisson
Summary: A variety of 4-phosphinylpyrrolidin-3-ones were synthesized via a [3+2] cycloaddition reaction between aryl aldonitrones and phosphinylallenes. The products were obtained as unique 4,5-trans diastereomers in yields ranging from 47% to 80% for 23 examples. Chiral racemic allenes exhibited a moderate 2:1 to 4:1 2,5-diastereoselectivity. Under the reaction conditions, the cycloadducts undergo a rearrangement to selectively afford the corresponding pyrrolidin-3-ones. DFT calculations provided insights into the mechanism involving the homolytic cleavage of the N-O bond of the cycloadduct.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Guo-Ke Zhang, Shu-Fang Wu, Chen Zhong, Yu-Qi Liu, Da-Hua Wang, Yu-Chen Zhang, Feng Shi
Summary: A copper-catalyzed alpha,beta-regioselective (2+4) cycloaddition of propargylic esters with o-hydroxyphenyl substituted secondary phosphine oxides (SPOs) was established, which afforded phosphorus-containing six-membered heterocycles in high yields. This reaction not only represents the first alpha,beta-regioselective (2+n) cycloaddition of propargylic esters via the intermediates of copper-allenylidenes, but also represents the first application of o-hydroxyphenyl substituted SPOs as 1,4-dinucleophiles in (2+4) cycloadditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Xin Yuan, Xuan Ke, Jiaxi Xu
Summary: In this study, various delta-phosphinolactones (delta-phostines) were efficiently and diastereospecifically synthesized through a series of chemical reactions. The synthesis features good to excellent yields, diastereospecificity, wide substrate scope, and other characteristics.
Article
Chemistry, Multidisciplinary
Kushal Dhake, Kyla J. Woelk, Joseph Becica, Andy Un, Sarah E. Jenny, David C. Leitch
Summary: The development of two divergent and complementary Lewis acid catalyzed additions of bicyclobutanes to imines is described. Microscale high-throughput experimentation was integral to the discovery and optimization of both reactions. N-arylimines undergo formal (3+2) cycloaddition with bicyclobutanes to yield azabicyclo[2.1.1]hexanes in a single step; in contrast, N-alkylimines undergo an addition/elimination sequence to generate cyclobutenyl methanamine products with high diastereoselectivity. These new products contain a variety of synthetic handles for further elaboration, including many functional groups relevant to pharmaceutical synthesis. The divergent reactivity observed is attributed to differences in basicity and nucleophilicity of the nitrogen atom in a common carbocation intermediate, leading to either nucleophilic attack (N-aryl) or E1 elimination (N-alkyl).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Lei Tang, Yuanjiu Xiao, Feng Wu, Jin-Lan Zhou, Tong-Tong Xu, Jian-Jun Feng
Summary: A silver-catalyzed dearomative cycloaddition strategy is described for the synthesis of indoline fused BCHs. It has high yields, wide functional group tolerance, and provides unexplored chemical space for drug design and development.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Oncology
Annette G. Beck-Sickinger, Daniel P. Becker, Oksana Chepurna, Bhaskar Das, Sebastian Flieger, Evamarie Hey-Hawkins, Narayan Hosmane, Satish S. Jalisatgi, Hiroyuki Nakamura, Rameshwar Patil, Maria da Graca H. Vicente, Clara Vinas
Summary: This article summarizes current research on the development of boron delivery drugs for boron neutron capture therapy, which were presented and discussed at the National Cancer Institute (NCI) Workshop on Neutron Capture Therapy held on April 20-22, 2022. The most commonly used boron sources are icosahedral boron clusters attached to various molecules such as peptides, proteins, porphyrin derivatives, dendrimers, polymers, and nanoparticles, as well as encapsulated into liposomes. These boron clusters and/or carriers can be labeled with contrast agents, allowing for imaging techniques like PET, SPECT, and fluorescence to quantify tumor-localized boron and serve as theranostic agents.
CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS
(2023)
Article
Chemistry, Medicinal
Liridona Useini, Marija Mojic, Markus Laube, Peter Loennecke, Sanja Mijatovic, Danijela Maksimovic-Ivanic, Jens Pietzsch, Evamarie Hey-Hawkins
Summary: Fenoprofen is a common NSAID used to treat rheumatoid arthritis, degenerative joint disease, ankylosing spondylitis, and gout. It inhibits the synthesis of prostaglandins by blocking both COX-1 and COX-2 isoforms. Modifications using carborane clusters showed stronger antitumor potential compared to aryl-based compounds.
Article
Pharmacology & Pharmacy
Sebastian Braun, Svetlana Paskas, Markus Laube, Sven George, Bettina Hofmann, Peter Loennecke, Dieter Steinhilber, Jens Pietzsch, Sanja S. Mijatovic, Danijela Maksimovic-Ivanic, Evamarie Hey-Hawkins
Summary: In this study, carborane-containing dual COX-2/5-LO inhibitors were designed by incorporating metabolically stable, sterically demanding, and hydrophobic carboranes into existing inhibitors. Five carborane-containing derivatives showed high inhibitory activities towards COX-2 and 5-LO, with meta-carborane derivative 3 demonstrating higher anticancer activity compared to RWJ-63556. The accumulation of lipid droplets in cells indicated the blockage of COX-2 and 5-LO pathways, suggesting a promising approach for the design of potent dual COX-2/5-LO inhibitors.
ADVANCED THERAPEUTICS
(2023)
Article
Chemistry, Multidisciplinary
Kyzgaldak Ramazanova, Peter Loennecke, Evamarie Hey-Hawkins
Summary: The reactive P-N bond in a racemic mixture of endo-1-phospha-2-azanorbornene (PAN) is cleaved with enantiomerically pure lithium alkoxides and protonation to produce diastereomeric mixtures of P-chiral 1-alkoxy-2,3-dihydrophosphole derivatives. The isolation of these compounds is challenging due to the reversibility of the reaction, but methylation and sulfur protection prevent elimination reaction. The resulting P-chiral diastereomeric 1-alkoxy-2,3-dihydrophosphole sulfide mixtures can be easily separated and characterized, and can be reduced to phosphorus(III) P-stereogenic 1-alkoxy-2,3-dihydrophospholes for use in asymmetric homogeneous transition metal catalysis.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Medicinal
Sebastian Braun, Svetlana Paskas, Markus Laube, Sven George, Bettina Hofmann, Peter Loennecke, Dieter Steinhilber, Jens Pietzsch, Sanja Mijatovic, Danijela Maksimovic-Ivanic, Evamarie Hey-Hawkins
Summary: The presence of inflammatory mediators in the tumor microenvironment indicates cancer-related inflammatory processes, and targeting these mediators and related signal pathways may provide a rational strategy for cancer treatment. This study focuses on incorporating carboranes into dual COX-2/5-LO inhibitors, key enzymes in eicosanoid biosynthesis. The results show that carborane-based tebufelone analogs exhibit no COX inhibition but 5-LO inhibitory activity, and structural modifications enhance their anticancer activity. Thus, this strategy is promising for designing potent 5-LO inhibitors with potential application as cytostatic agents.
Article
Chemistry, Medicinal
Philipp Stockmann, Lydia Kuhnert, Lisa Zoerner, Walther Honscha, Evamarie Hey-Hawkins
Summary: The role of ATP-binding cassette (ABC) transporter-mediated multidrug resistance (MDR) in anti-cancer therapy is challenging, as cancer cells exploit efflux transporters like BCRP to secrete chemotherapeutic substances. In this study, a hybrid BCRP inhibitor was designed by combining a prominent scaffold N-phenylquinazolin-4-amine with a boron-carbon cluster. The resulting compound showed increased inhibitory activity towards human ABCG2 and the ability to reverse drug resistance.
Article
Biochemistry & Molecular Biology
Vera V. Khrizanforova, Robert R. Fayzullin, Tatiana P. Gerasimova, Mikhail N. Khrizanforov, Almaz A. Zagidullin, Daut R. Islamov, Anton N. Lukoyanov, Yulia H. Budnikova
Summary: The redox properties of monoiminoacenaphthenes (MIANs) were investigated using various electrochemical techniques. The obtained potential values were used to calculate the electrochemical gap and frontier orbital difference energy. The reduction of MIANs at the first peak potential was carried out, yielding two-electron one-proton addition products through controlled potential electrolysis. The structures of three new sodium complexes, three electrochemical reduction products, and one NaBH4 reduction product were determined by single-crystal X-ray diffraction.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
Almaz A. Zagidullin, Alena R. Lakomkina, Mikhail N. Khrizanforov, Robert R. Fayzullin, Kirill V. Kholin, Tatiana P. Gerasimova, Ruslan P. Shekurov, Ilya A. Bezkishko, Vasili A. Miluykov
Summary: Heteroleptic 2,3,4,5-tetraphenyl-1-monophosphaferrocene was synthesized by reacting lithium 2,3,4,5-tetraphenyl-1-monophosphacyclopentadienide with [FeCp(eta(6)-C6H5CH3)][PF6]. The structure of the compound was confirmed by NMR and X-ray diffraction, and its oxidation behavior was studied by cyclic voltammetry. Comparison with a W(CO)(5)-complex showed the possibility of changing the coordination type during oxidation.
Article
Biochemistry & Molecular Biology
Sebastian Braun, Sanja Jelaca, Markus Laube, Sven George, Bettina Hofmann, Peter Loennecke, Dieter Steinhilber, Jens Pietzsch, Sanja Mijatovic, Danijela Maksimovic-Ivanic, Evamarie Hey-Hawkins
Summary: Targeting inflammatory mediators and related pathways is a rational strategy for cancer treatment. Incorporating carboranes into dual COX-2/5-LO inhibitors shows promise, with compounds exhibiting high 5-LO inhibitory activities. However, carborane analogs demonstrate lower anticancer activity compared to related compounds in cell viability studies. R-830-Cb, a carborane-based analog, shows potential for further mechanistic and in vivo studies due to the advantages of boron cluster incorporation.
Article
Chemistry, Inorganic & Nuclear
Almaz L. L. Zinnatullin, Almaz A. A. Zagidullin, Liudmila I. I. Savostina, Ilya A. A. Bezkishko, Andrey V. V. Petrov, Evgeny N. N. Dulov, Rustem R. R. Zairov, Vasily A. A. Miluykov, Farit G. G. Vagizov
Summary: A series of phosphaferrocenes with different numbers of phosphorus atoms and phenyl groups in the cyclopentadienyl ring were synthesized and studied using Mo''ssbauer spectroscopy. The revealed Mo''ssbauer hyperfine parameters were consistent with density functional theory calculations. Substituting CH units with phosphorus atoms in the cyclopentadienyl ring was found to affect the population of molecular orbitals related to iron, leading to changes in Mo''ssbauer hyperfine parameters, especially quadrupole splitting values. Intermolecular vibrations were analyzed using the Debye model, and characteristic lattice Debye temperatures and intermolecular force constants were calculated for each sample.
Article
Crystallography
Ilyas F. Sakhapov, Almaz A. Zagidullin, Alexey B. Dobrynin, Igor A. Litvinov, Dmitry G. Yakhvarov, Mikhail A. Bondarenko, Alexander S. Novikov, Vladimir P. Fedin, Sergey A. Adonin
Summary: The crystal structure of 3,3',5,5'-tetrabromo-4,4'-bipyridine (BrBipy, 1) was determined, and the non-covalent interactions in solid state were investigated using theoretical methods. By using BrBipy as a linker ligand, a 1D coordination polymer {[Co(BrBipy)(NO3)(2)(CH3OH)(2)]} (2) was synthesized and characterized.
Article
Chemistry, Multidisciplinary
R. R. Amirov, KhA. Akhmadiev, A. M. Gaifutdinov, K. A. Andrianova, A. Shmelev, A. K. Gatiatulin, A. A. Zagidullin, V. A. Milyukov, L. M. Amirova
Summary: The interaction between phosphorus-containing epoxy trifunctional monomer - triglycidyl phosphate (TGPhT) and europium (III) nitrate hexahydrate is investigated. The addition of europium salt into TGPhT leads to its dissolution, accompanied by the opening reaction and the formation of a polymer. FTIR spectroscopy and DSC are used to study the interaction between triepoxide and salt. The thermal stability of the samples is determined using TG/DSC, and the gaseous products evolved during thermal analysis are identified using quadrupole mass spectrometry. Kinetic parameters of the curing reaction are computed. The interaction between TGPhT and europium nitrate is suggested to occur through the opening of epoxy rings via cationic polymerization, resulting in a cured epoxy polymer with luminescent properties.
MATERIALS TODAY CHEMISTRY
(2023)
Editorial Material
Chemistry, Multidisciplinary
Kyzgaldak Ramazanova, Peter Loennecke, Evamarie Hey-Hawkins
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Kyzgaldak Ramazanova, Soumyadeep Chakrabortty, Fabian Kallmeier, Nadja Kretzschmar, Sergey Tin, Peter Loennecke, Johannes G. de Vries, Evamarie Hey-Hawkins
Summary: Sulfur-protected enantiopure P-chiral 1-phosphanorbornane silyl ethers 5a,b were obtained in high yields via reaction with tert-butyldimethylsilyl chloride (TBDMSCl) and triphenylsilyl chloride (TPSCl), and were subsequently purified and characterized. The bulky monodentate enantiopure phosphorus(III) 1-phosphanorbornane silyl ethers 6a,b were obtained by desulfurization with excess Raney nickel, and showed better activity and selectivity as ligands in iridium-catalyzed asymmetric hydrogenation.
Article
Biochemistry & Molecular Biology
Kyzgaldak Ramazanova, Anna Karina Mueller, Peter Loennecke, Oldamur Holloczki, Barbara Kirchner, Evamarie Hey-Hawkins
Summary: The reactive P-N bond can be cleaved by simple alcohols in 1-phospha-2-azanorbornenes, resulting in a racemic mixture of P-chiral 2,3-dihydrophosphole derivatives. The reversibility of the reaction prevents the isolation of the products, but sulfurization of the phosphorus atom can block the reaction and yield structurally characterized compounds.
