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A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-18 Andrew D. Gillie, Matthew G. Wakeling, Bethan L. Greene, Louise Male, Paul W. Davies
Abstract A polysubstituted 3-aminoimidazo[5,1-b]oxazol-6-ium framework has been accessed from a new nitrenoid reagent by a two-step ynamide annulation and imidazolium ring-formation sequence. Metalation with Au(I), Cu(I) and Ir(I) at the C2 position provides an L-shaped NHC ligand scaffold that has been validated in gold-catalysed alkyne hydration and arylative cyclisation reactions. Beilstein J. Org
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Chemical and biosynthetic potential of Penicillium shentong XL-F41 Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-15 Ran Zou, Xin Li, Xiaochen Chen, Yue-Wei Guo, Baofu Xu
Abstract Penicillium strains are renowned for producing diverse secondary metabolites with unique structures and promising bioactivities. Our chemical investigations, accompanied by fermentation media optimization, of a newly isolated fungus, Penicillium shentong XL-F41, led to the isolation of twelve compounds. Among these are two novel indole terpene alkaloids, shentonins A and B (1 and 2), and a
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Introduction of a human- and keyboard-friendly N-glycan nomenclature Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-15 Friedrich Altmann, Johannes Helm, Martin Pabst, Johannes Stadlmann
Abstract In the beginning was the word. But there were no words for N-glycans, at least, no simple words. Next to chemical formulas, the IUPAC code can be regarded as the best, most reliable and yet immediately comprehensible annotation of oligosaccharide structures of any type from any source. When it comes to N-glycans, the venerable IUPAC code has, however, been widely supplanted by highly simplified
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A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-14 Michael O. Akintubosun, Melanie A. Higgins
Abstract Hygromycin A is a broad-spectrum antibiotic that contains a furanose, cinnamic acid, and aminocyclitol moieties. The biosynthesis of the aminocyclitol has been proposed to proceed through six enzymatic steps from glucose 6-phosphate through myo-inositol to the final methylenedioxy-containing aminocyclitol. Although there is some in vivo evidence for this proposed pathway, biochemical support
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Recent developments in the engineered biosynthesis of fungal meroterpenoids Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-13 Zhiyang Quan, Takayoshi Awakawa
Abstract Meroterpenoids are hybrid compounds that are partially derived from terpenoids. This group of natural products displays large structural diversity, and many members exhibit beneficial biological activities. This mini-review highlights recent advances in the engineered biosynthesis of meroterpenoid compounds with C15 and C20 terpenoid moieties, with the reconstruction of fungal meroterpenoid
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Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-11 Vladimir P. Rybalkin, Sofiya Yu. Zmeeva, Lidiya L. Popova, Irina V. Dubonosova, Olga Yu. Karlutova, Oleg P. Demidov, Alexander D. Dubonosov, Vladimir A. Bren
Abstract A series of novel photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline receptor substituent was synthesized. Upon irradiation in acetonitrile or DMSO with light of 436 nm, they underwent Z–E isomerization of the C=C bond, followed by very fast N→O migration of the acyl group and the formation of nonemissive O-acylated isomers. These
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Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-11 Alexander Yanovich, Anastasia Vepreva, Ksenia Malkova, Grigory Kantin, Dmitry Dar’in
Abstract A facile approach to novel medicinally relevant spiro heterocyclic scaffolds (namely furan-2(5H)-ones, tetrahydrofurans and pyrans spiro-conjugated with the succinimide ring) has been developed. The protocol consists of Rh(II)-catalyzed insertion of heterocyclic carbenes derived from diazoarylidene succinimides (DAS) into the O–H bond of propiolic/allenic acids or brominated alcohols, followed
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Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-11 Yasuhiro Oishi, Motoharu Kitatani, Koichi Kusakabe
Abstract We theoretically analyze possible multiple conformations of protein molecules immobilized by 1-pyrenebutanoic acid succinimidyl ester (PASE) linkers on graphene. The activation barrier between two bi-stable conformations exhibited by PASE is confirmed to be based on the steric hindrance effect between a hydrogen on the pyrene group and a hydrogen on the alkyl group of this molecule. Even after
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Switchable molecular tweezers: design and applications Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-01 Pablo Msellem, Maksym Dekthiarenko, Nihal Hadj Seyd, Guillaume Vives
Abstract Switchable molecular tweezers are a unique class of molecular switches that, like their macroscopic analogs, exhibit mechanical motion between an open and closed conformation in response to stimuli. Such systems constitute an essential component of artificial molecular machines. This review will present selected examples of switchable molecular tweezers and their potential applications. The
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Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-01 Jens Frackenpohl, David M. Barber, Guido Bojack, Birgit Bollenbach-Wahl, Ralf Braun, Rahel Getachew, Sabine Hohmann, Kwang-Yoon Ko, Karoline Kurowski, Bernd Laber, Rebecca L. Mattison, Thomas Müller, Anna M. Reingruber, Dirk Schmutzler, Andrea Svejda
Abstract The present work covers novel herbicidal lead structures that contain a 2,3-dihydro[1,3]thiazolo[4,5-b]pyridine scaffold as structural key feature carrying a substituted phenyl side chain. These new compounds show good acyl-ACP thioesterase inhibition in line with strong herbicidal activity against commercially important weeds in broadacre crops, e.g., wheat and corn. The desired substituted
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Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-29 Ruichen Lan, Brock Yager, Yoonsun Jee, Cynthia S. Day, Amanda C. Jones
Abstract Kinetic studies on the intramolecular hydroamination of protected variants of 2,2-diphenylpent-4-en-1-amine were carried out under a variety of conditions with cationic gold catalysts supported by phosphine ligands. The impact of ligand on gold, protecting group on nitrogen, and solvent and additive on reaction rates was determined. The most effective reactions utilized more Lewis basic ureas
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A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001 Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-29 Rattiya Janthanom, Yuta Kikuchi, Hiroki Kanto, Tomoyasu Hirose, Arisu Tahara, Takahiro Ishii, Arinthip Thamchaipenet, Yuki Inahashi
Abstract Actinomycetes are well-known as the main producers of bioactive compounds such as antibiotics, anticancers, and immunosuppressants. Screening of natural products from actinomycetes has been an essential part of several drug discovery programs. Finding such novel biologically active metabolites is immensely important because of their beneficial health effects. Recently, the discovery of new
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Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-28 Alexander S. Hampton, David R. W. Hodgson, Graham McDougald, Linhua Wang, Graham Sandford
Abstract Solutions of 1,3-diketones and 1,3-ketoester derivatives react with fluorine to give the corresponding 2,2-difluoro-1,3-dicarbonyl derivatives in the presence of quinuclidine. Quinuclidine reacts with fluorine in situ to generate a fluoride ion that facilitates limiting enolization processes, and an electrophilic N–F fluorinating agent that is reactive towards neutral enol species. Beilstein
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Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793 Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-28 Zhen Ying, Xiao-Ming Li, Sui-Qun Yang, Hong-Lei Li, Xin Li, Bin-Gui Wang, Ling-Hong Meng
Abstract Pseudallenes A and B (1 and 2), the new and rare examples of sulfur-containing ovalicin derivatives, along with three known analogues 3–5, were isolated and identified from the culture extract of Pseudallescheria boydii CS-793, a fungus obtained from the deep-sea cold seep sediments. Their structures were established by detailed interpretation of NMR spectroscopic and mass spectrometric data
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(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-27 Nataliia V. Kirij, Andrey A. Filatov, Yurii L. Yagupolskii, Sheng Peng, Lee Sprague
Abstract A series of 2,3-dihalo-1,1,1,4,4,4-hexafluorobutanes and 2-halo-1,1,1,4,4,4-hexafluorobut-2-enes were prepared from commercially available hydrofluoroolefins 1,1,1,4,4,4-hexafluorobut-2-enes and their 1H, 19F and 13C chemical shifts measured. Some reactions of synthesized 2-halo-1,1,1,4,4,4-hexafluorobut-2-enes have been investigated. A simple, one-pot procedure for the preparation of a new
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Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-26 Fumihiro Ishikawa, Sho Konno, Hideaki Kakeya, Genzoh Tanabe
Abstract The adenylation (A) domain is essential for non-ribosomal peptide synthetases (NRPSs), which synthesize various peptide-based natural products, including virulence factors, such as siderophores and genotoxins. Hence, the inhibition of A-domains could attenuate the virulence of pathogens. 5’-O-N-(Aminoacyl or arylacyl)sulfamoyladenosine (AA-AMS) is a bisubstrate small-molecule inhibitor of
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Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-23 Nahed Ketata, Linhao Liu, Ridha Ben Salem, Henri Doucet
Abstract The Pd-catalyzed annulative π-extension of 1,8-dibromonaphthalene for the preparation of fluoranthenes in a single operation has been investigated. With specific arenes such as fluorobenzenes, the Pd-catalyzed double functionalization of C–H bonds yields the desired fluoranthenes. The reaction proceeds via a palladium-catalyzed direct intermolecular arylation, followed by a direct intramolecular
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Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-23 Eiichi Kayahara, Yoshiyuki Mizuhata, Shigeru Yamago
Abstract A dication of [5]cycloparaphenylene ([5]CPP2+) was selectively encapsulated by neutral [10]CPP to form the shortest double-layer carbon nanotube, [10]CPP⊃[5]CPP2+. While the same host–guest complex consisted of neutral CPPs, [10]CPP⊃[5]CPP, was already reported, the cationic complex showed an about 20 times higher association constant in (CDCl2)2 at 25 °C (103 mol L−1). Electrochemical and
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Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-22 Periklis X. Kolagkis, Eirini M. Galathri, Christoforos G. Kokotos
Abstract The synthesis of indoles and their derivatives, more specifically bis(indolyl)methanes (BIMs), has been an area of great interest in organic chemistry, since these compounds exhibit a range of interesting biological and pharmacological properties. BIMs are naturally found in cruciferous vegetables and have been shown to be effective antifungal, antibacterial, anti-inflammatory, and even anticancer
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Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-21 Eugeny Ivakhnenko, Vasily Malay, Pavel Knyazev, Nikita Merezhko, Nadezhda Makarova, Oleg Demidov, Gennady Borodkin, Andrey Starikov, Vladimir Minkin
Abstract A convenient method for the synthesis of a series of 2-(arylamino)-3H-phenoxazin-3-ones based on the nucleophilic substitution reaction between sterically crowded 3H-phenoxazin-3-one and arylamines performed by short-term heating of the melted reactants at 220–250 °C is described, and the compounds were characterized by means of single-crystal X-ray crystallography, NMR, UV–vis, and IR spectroscopy
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Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-21 Carlos R. Azpilcueta-Nicolas, Jean-Philip Lumb
Abstract Due to their ease of preparation, stability, and diverse reactivity, N-hydroxyphthalimide (NHPI) esters have found many applications as radical precursors. Mechanistically, NHPI esters undergo a reductive decarboxylative fragmentation to provide a substrate radical capable of engaging in diverse transformations. Their reduction via single-electron transfer (SET) can occur under thermal, photochemical
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Spatial arrangements of cyclodextrin host–guest complexes in solution studied by 13C NMR and molecular modelling Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-20 Konstantin Lebedinskiy, Ivan Barvík, Zdeněk Tošner, Ivana Císařová, Jindřich Jindřich, Radim Hrdina
Abstract 13C NMR spectroscopic analyses of Cs symmetric guest molecules in the cyclodextrin host cavity, combined with molecular modelling and solid-state X-ray analysis, provides a detailed description of the spatial arrangement of cyclodextrin host–guest complexes in solution. The chiral cavity of the cyclodextrin molecule creates an anisotropic environment for the guest molecule resulting in a splitting
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Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-19 Jon Lundstrøm, Emilie Gillon, Valérie Chazalet, Nicole Kerekes, Antonio Di Maio, Ten Feizi, Yan Liu, Annabelle Varrot, Daniel Bojar
Abstract Plant lectins have garnered attention for their roles as laboratory probes and potential therapeutics. Here, we report the discovery and characterization of Cucumis melo agglutinin (CMA1), a new R-type lectin from melon. Our findings reveal CMA1’s unique glycan-binding profile, mechanistically explained by its 3D structure, augmenting our understanding of R-type lectins. We expressed CMA1
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Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-19 Sharmila Neupane, Marcelo Rodrigues de Amorim, Elizabeth Skellam
Abstract Several under-explored Aspergillus sp. produce intriguing heptapeptides containing a γ-aminobutyric acid (GABA) residue with as yet unknown biological functions. In this study, a new GABA-containing heptapeptide – unguisin J (1) – along with known unguisin B (2) were isolated from a solid culture of Aspergillus heteromorphus CBS 117.55. The structure of compound 1 was elucidated by extensive
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Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-15 Aissam Okba, Pablo Simón Marqués, Kyohei Matsuo, Naoki Aratani, Hiroko Yamada, Gwénaël Rapenne, Claire Kammerer
Abstract The “precursor approach” has proved particularly valuable for the preparation of insoluble and unstable π-conjugated polycyclic compounds (π-CPCs), which cannot be synthesized via in-solution organic chemistry, for their improved processing, as well as for their electronic investigation both at the material and single-molecule scales. This method relies on the synthesis and processing of soluble
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Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-14 Wenqing Hao, Long Wang, Jinlei Zhang, Dawei Teng, Guorui Cao
Abstract A simple and efficient method for the synthesis of spiropyridazine-benzosultams has been developed by means of [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes. This approach displays advantages such as mild reaction conditions, wide substrate range tolerance, simple operation, compatibility with gram-scale preparation. Beilstein J. Org.
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Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C70 production Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-13 Cristina Castanyer, Anna Pla-Quintana, Anna Roglans, Albert Artigas, Miquel Solà
Abstract The regioselective functionalization of fullerenes holds significant promise for applications in the fields of medicinal chemistry, materials science, and photovoltaics. In this study, we investigate the regioselectivity of the rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions between diynes and C70 as a novel procedure for generating C70 bis(fulleroid) derivatives. The aim is to shed
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Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-12 Kazuhiro Okamoto, Naoki Shida, Mahito Atobe
Abstract Electrochemically generated amidyl radical species produced distinct inter- or intramolecular hydroamination reaction products via a proton-coupled electron transfer (PCET) mechanism. Cyclic voltammetry (CV) analysis indicated that the chemoselectivity was derived from the size of the hydrogen bond complex, which consisted of the carbamate substrate and phosphate base, and could be controlled
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Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-08 Ekaterina V. Kolupaeva, Narek A. Dzhangiryan, Alexander F. Pozharskii, Oleg P. Demidov, Valery A. Ozeryanskii
Abstract The possibility of functionalization of dipyrido[3,2-e:2′,3′-h]acenaphthene containing a quino[7,8-h]quinoline fragment and being a highly basic diazine analog of 1,8-bis(dimethylamino)naphthalene (“proton sponge”) has been studied for the first time. In addition to the pronounced tendency of the title compound to form associates with an intramolecular hydrogen bond of the NHN type (new examples
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Catalytic multi-step domino and one-pot reactions Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-08 Svetlana B. Tsogoeva
Beilstein J. Org. Chem. 2024, 20, 254–256. doi:10.3762/bjoc.20.25
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Nucleophilic functionalization of thianthrenium salts under basic conditions Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-08 Xinting Fan, Duo Zhang, Xiangchuan Xiu, Bin Xu, Yu Yuan, Feng Chen, Pan Gao
Abstract In recent years, S-(alkyl)thianthrenium salts have become an important means of functionalizing alcohol compounds. However, additional transition metal catalysts and/or visible light are required. Herein, a direct thioetherification/amination reaction of thianthrenium salts is realized under metal-free conditions. This strategy exhibits good functional-group tolerance, operational simplicity
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Photochromic derivatives of indigo: historical overview of development, challenges and applications Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-07 Gökhan Kaplan, Zeynel Seferoğlu, Daria V. Berdnikova
Abstract The importance of indigo dyes is constantly increasing with the evolution of novel textile materials and photochromic material technologies. The aim of this review article is to provide a comprehensive overview of the development of photochromic indigo derivatives from the first report on the photochromic N,N'-diacetylindigo in 1954 until now. We begin with the list of historical milestones
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Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-06 Milandip Karak, Cian R. Cloonan, Brad R. Baker, Rachel V. K. Cochrane, Stephen A. Cochrane
Abstract Lipid II is an essential glycolipid found in bacteria. Accessing this valuable cell wall precursor is important both for studying cell wall synthesis and for studying/identifying novel antimicrobial compounds. Herein, we describe optimizations to the modular chemical synthesis of lipid II and unnatural analogues. In particular, the glycosylation step, a critical step in the formation of the
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Copper-catalyzed multicomponent reaction of β-trifluoromethyl β-diazo esters enabling the synthesis of β-trifluoromethyl N,N-diacyl-β-amino esters Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-02 Youlong Du, Haibo Mei, Ata Makarem, Ramin Javahershenas, Vadim A. Soloshonok, Jianlin Han
Abstract An efficient multicomponent reaction of newly designed β-trifluoromethyl β-diazo esters, acetonitrile, and carboxylic acids via an interrupted esterification process under copper-catalyzed conditions has been developed, which affords various unsymmetrical β-trifluoromethyl N,N-diacyl-β-amino esters in good to excellent yields. The reaction features mild conditions, a wide scope of β-amino
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Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-02-01 Yumei Wang, Guangzhu Wang, Yanping Zhu, Kaiwu Dong
Abstract A convenient and efficient method for the synthesis of optically active difluoro-substituted indoline derivatives starting from the corresponding 3H-indoles by chiral phosphoric acid-catalyzed transfer hydrogenation was developed. Using Hantzsch ester as the hydrogen source under mild reaction conditions, the target products can be obtained with excellent yield and enantioselectivity. Beilstein
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Comparison of glycosyl donors: a supramer approach Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-31 Anna V. Orlova, Nelly N. Malysheva, Maria V. Panova, Nikita M. Podvalnyy, Michael G. Medvedev, Leonid O. Kononov
Abstract The development of new methods for chemical glycosylation commonly includes comparison of various glycosyl donors. An attempted comparison of chemical properties of two sialic acid-based thioglycoside glycosyl donors, differing only in the substituent at O-9 (trifluoroacetyl vs chloroacetyl), at different concentrations (0.05 and 0.15 mol·L−1) led to mutually excluding conclusions concerning
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Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-31 Amina Moutayakine, Anthony J. Burke
Abstract A sequential strategy to access 10,11-dihydro-5H-dibenzo[b,e][1,4]diazepinones (DBDAPs) is disclosed in this article through a palladium and copper-catalyzed amination (Buchwald–Hartwig (B–H) or Chan–Lam (C–L)) followed by a palladium-catalyzed intramolecular aminocarbonylation with Mo(CO)6 as CO surrogate (to avoid toxic CO handling) of readily available o-phenylenediamines and either 1,2-dibromobenzene
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Synthesis of the 3’-O-sulfated TF antigen with a TEG-N3 linker for glycodendrimersomes preparation to study lectin binding Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-30 Mark Reihill, Hanyue Ma, Dennis Bengtsson, Stefan Oscarson
Abstract The synthesis of gram quantities of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc) and its 3’-sulfated analogue with a TEG-N3 spacer attached is described. The synthesis of the TF antigen comprises seven steps, from a known N-Troc-protected galactosamine donor, with an overall yield of 31%. Both the spacer (85%) and the galactose moiety (79%) were introduced using thioglycoside donors in NIS/AgOTf-promoted
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Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-25 Viktoria A. Ikonnikova, Cristina Cheibas, Oscar Gayraud, Alexandra E. Bosnidou, Nicolas Casaretto, Gilles Frison, Bastien Nay
Abstract The Hock cleavage, which is compatible with tandem processes, was applied to the synthesis of 1-aryltetralines through a one-pot transformation from readily available benzyl(prenyl)malonate substrates. After the photooxygenation of the prenyl moiety, the resulting hydroperoxide was directly engaged in a Hock cleavage by adding a Lewis acid. The presence of an aromatic nucleophile in the reaction
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Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-23 Changdong Shao, Chen Ma, Li Li, Jingyi Liu, Yanan Shen, Chen Chen, Qionglin Yang, Tianyi Xu, Zhengsong Hu, Yuhe Kan, Tingting Zhang
Abstract An efficient and practical method for the synthesis of C5-brominated 8-aminoquinoline amides via a copper-promoted selective bromination of 8-aminoquinoline amides with alkyl bromides was developed. The reaction proceeds smoothly in dimethyl sulfoxide (DMSO) under air, employing activated and unactivated alkyl bromides as the halogenation reagents without additional external oxidants. This
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Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-22 Michio Yamada
Abstract Various push–pull chromophores can be synthesized in a single and atom-economical step through [2 + 2] cycloaddition–retroelectrocyclization (CA–RE) reactions involving diverse electron-rich alkynes and electron-deficient alkenes. In this review, a comprehensive investigation of the recent and noteworthy advancements in the research on push–pull chromophores prepared via the [2 + 2] CA–RE
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Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-19 Chuan Yang, Wei Shi, Jian Tian, Lin Guo, Yating Zhao, Wujiong Xia
Abstract A visible-light-promoted research protocol for constructing dihydropyrido[1,2-a]indolone skeletons is herein described proceeding through a cascade cyclization mediated by trifluoromethyl radicals. This method allows the efficient synthesis of various indole derivatives without the need of photocatalysts or transition-metal catalysts. Mechanism experiments indicate that the process involves
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Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-18 Julika Schlosser, Olga Fedorova, Yuri Fedorov, Heiko Ihmels
Abstract The photoreactions of selected styrylpyridine derivatives to the corresponding benzo[c]quinolizinium ions are described. It is shown that these reactions are more efficient in aqueous solution (97–44%) than in organic solvents (78–20% in MeCN). The quinolizinium derivatives bind to DNA by intercalation with binding constants of 6–11 × 104 M−1, as shown by photometric and fluorimetric titrations
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Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-17 Laura Abella, Gerard Novell-Leruth, Josep M. Ricart, Josep M. Poblet, Antonio Rodríguez-Fortea
Abstract Fullerene dimerization inside a peapod is analyzed at DFT level by characterizing the stationary points and deriving the energy profile of the initial and reversible process named phase 1. We find that the barriers for the radical cation mechanism are significantly lower than those found for the neutral pathway. The peapod is mainly providing one-dimensional confinement for the reaction to
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Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-16 Pengcheng Li, Daniel Kowalczyk, Johannes Liessem, Mohamed M. Elnagar, Dariusz Mitoraj, Radim Beranek, Dirk Ziegenbalg
Abstract Photocatalytic hydrogen production from water is a promising way to fulfill energy demands and attain carbon emission reduction goals effectively. In this study, a loop photoreactor with a total volume of around 500 mL is presented for the photocatalytic hydrogen evolution using a Pt-loaded polymeric carbon nitride photocatalyst under 365 nm irradiation in the presence of sacrificial reducing
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Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-15 Christina Schøttler, Kasper Lund-Rasmussen, Line Broløs, Philip Vinterberg, Ema Bazikova, Viktor B. R. Pedersen, Mogens Brøndsted Nielsen
Abstract Large donor–acceptor scaffolds derived from polycyclic aromatic hydrocarbons (PAHs) with tunable HOMO and LUMO energies are important for several applications, such as organic photovoltaics. Here, we present a large selection of PAHs based on central indenofluorene (IF) or fluorene cores and containing various dithiafulvene (DTF) donor units that gain aromaticity upon oxidation and a variety
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Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-11 Keiko Kojima, Nodoka Kosugi, Hirokuni Jintoku, Kazufumi Kobashi, Toshiya Okazaki
Abstract We successfully prepared a surfactant-assisted carbon nanotube (CNT) liquid crystal (LC) dispersion with double-walled CNTs (DWCNTs) having a high aspect ratio (≈1378). Compared to dispersions of single-walled CNTs (SWCNTs) with lower aspect ratio, the transition concentrations from isotropic phase to biphasic state, and from biphasic state to nematic phase are lowered, which is consistent
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Using the phospha-Michael reaction for making phosphonium phenolate zwitterions Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-10 Matthias R. Steiner, Max Schmallegger, Larissa Donner, Johann A. Hlina, Christoph Marschner, Judith Baumgartner, Christian Slugovc
Abstract The reactions of 2,4-di-tert-butyl-6-(diphenylphosphino)phenol and various Michael acceptors (acrylonitrile, acrylamide, methyl vinyl ketone, several acrylates, methyl vinyl sulfone) yield the respective phosphonium phenolate zwitterions at room temperature. Nine different zwitterions were synthesized and fully characterized. Zwitterions with the poor Michael acceptors methyl methacrylate
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Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-08 Lorenzo Catti, Shinji Aoyama, Michito Yoshizawa
Abstract Efficient water-solubilization of nanocarbons is desirable for both their biological and material applications, but so far has mainly relied on covalent modifications or amphiphiles featuring ionic side-chains. Here, we report a facile 2–4-step synthesis of pyridinium-based, bent aromatic amphiphiles with modular nonionic side-chains (i.e., CH3 and CH2CH2(OCH2CH2)2–Y (Y = OCH3, OH, and imidazole))
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Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-05 Pavel S. Silaichev, Tetyana V. Beryozkina, Vsevolod V. Melekhin, Valeriy O. Filimonov, Andrey N. Maslivets, Vladimir G. Ilkin, Wim Dehaen, Vasiliy A. Bakulev
Abstract A novel and efficient base-catalyzed, transition-metal-free method for the synthesis of diheterocyclic compounds connected by an amidine linker, including apart from the common 1,2,3-triazole ring, either an additional pyrimidinedione, 4-nitroimidazole, isoxazole, 1,3,4-triazole, 2-oxochromone or thiazole ring, has been developed. The process was facilitated by a strong base and includes the
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NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-05 Luc Patiny, Hamed Musallam, Alejandro Bolaños, Michaël Zasso, Julien Wist, Metin Karayilan, Eva Ziegler, Johannes C. Liermann, Nils E. Schlörer
Abstract NMRium is the first web-based software that allows displaying, processing, interpretation, and teaching of 1D and 2D NMR data in a user-friendly interface. It can import the most common data formats (e.g., JCAMP-DX, Bruker, Varian, and Jeol). While the scope for the use of NMRium encompasses a variety of applications such as being a component in data repositories or electronic lab notebooks
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Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-04 Nils Clamor, Mattis Damrath, Thomas J. Kuczmera, Daniel Duvinage, Boris J. Nachtsheim
Abstract N-Acyl carbazoles can be efficiently produced through a single-step process using amides and cyclic diaryliodonium triflates. This convenient reaction is facilitated by copper iodide in p-xylene, using the commonly found activating ligand diglyme. We have tested this method with a wide range of amides and iodonium triflates, proving its versatility with numerous substrates. Beyond carbazoles
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Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-01-02 Seiji Kawai, Akito Yamada, Yohei Katsuyama, Yasuo Ohnishi
Abstract Recently, we identified the biosynthetic gene cluster of avenalumic acid (ava cluster) and revealed its entire biosynthetic pathway, resulting in the discovery of a diazotization-dependent deamination pathway. Genome database analysis revealed the presence of more than 100 ava cluster-related biosynthetic gene clusters (BGCs) in actinomycetes; however, their functions remained unclear. In
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1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF3: the case of alkyne hydration. Chemistry vs electrochemistry Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-28 Marta David, Elisa Galli, Richard C. D. Brown, Marta Feroci, Fabrizio Vetica, Martina Bortolami
Abstract In order to replace the expensive metal/ligand catalysts and classic toxic and volatile solvents, commonly used for the hydration of alkynes, the hydration reaction of alkynes was studied in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF4) adding boron trifluoride diethyl etherate (BF3·Et2O) as catalyst. Different ionic liquids were used, varying the cation or the
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Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-21 Yipeng Yin, Reed Arneson, Alexander Apostle, Adikari M. D. N. Eriyagama, Komal Chillar, Emma Burke, Martina Jahfetson, Yinan Yuan, Shiyue Fang
Abstract Long oligodeoxynucleotides (ODNs) are segments of DNAs having over one hundred nucleotides (nt). They are typically assembled using enzymatic methods such as PCR and ligation from shorter 20 to 60 nt ODNs produced by automated de novo chemical synthesis. While these methods have made many projects in areas such as synthetic biology and protein engineering possible, they have various drawbacks
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Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-20 Nedra Touj, François Mazars, Guillermo Zaragoza, Lionel Delaude
Abstract The synthesis of zwitterionic dithiocarboxylate adducts was achieved by deprotonating various aldiminium or 1,2,3-triazolium salts with a strong base, followed by the nucleophilic addition of the in situ-generated cyclic (alkyl)(amino) or mesoionic carbenes (CAACs or MICs) onto carbon disulfide. Nine novel compounds were isolated and fully characterized by 1H and 13C NMR, FTIR, and HRMS techniques
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Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-19 Mateusz Marcisz, Sebastian Anila, Margrethe Gaardløs, Martin Zacharias, Sergey A. Samsonov
Abstract In the past few decades, glycosaminoglycan (GAG) research has been crucial for gaining insights into various physiological, pathological, and therapeutic aspects mediated by the direct interactions between the GAG molecules and diverse proteins. The structural and functional heterogeneities of GAGs as well as their ability to bind specific proteins are determined by the sugar composition of
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Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-18 Xing Liu, Wenjing Shi, Jing Sun, Chao-Guo Yan
Abstract A straightforward synthetic protocol for the efficient construction of diazepine-containing spiroindolines has been developed and proceeds through a by base-promoted annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates. The reaction mechanism of this formal [4 + 3] annulation includes the in situ generated allylic ylide, nucleophilic substitution, Michael
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Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-14 Kan Tang, Megan R. Brown, Chad Risko, Melissa K. Gish, Garry Rumbles, Phuc H. Pham, Oana R. Luca, Stephen Barlow, Seth R. Marder
Abstract 2,2’-Bis(4-dimethylaminophenyl)- and 2,2'-dicyclohexyl-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[d]imidazole ((N-DMBI)2 and (Cyc-DMBI)2) are quite strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced
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Biphenylene-containing polycyclic conjugated compounds Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2023-12-13 Cagatay Dengiz
Abstract There has been a growing emphasis on the synthesis of polycyclic conjugated compounds, driven by their distinct structural characteristics that make them valuable candidates for use in cutting-edge technologies. In particular, acenes, a subgroup of polycyclic aromatic compounds, are sought-after synthetic targets due to their remarkable optoelectronic properties which stem from their π-conjugation