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Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-18 Ke Jiang, Cheng Pan, Limin Wang, Hao-Yang Wang, Jianwei Han
Abstract Cyclic annulation involving diaryliodonium salts is an efficient tool for the construction of two or more chemical bonds in a one-pot process. Ortho-functionalized diaryliodonium salts have showcased distinct reactivity in the exploration of benzocyclization or arylocyclization. With this strategy of ortho-ester-substituted diaryliodonium salts, herein, we utilized a copper catalyst to activate
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Confirmation of the stereochemistry of spiroviolene Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-18 Yao Kong, Yuanning Liu, Kaibiao Wang, Tao Wang, Chen Wang, Ben Ai, Hongli Jia, Guohui Pan, Min Yin, Zhengren Xu
Abstract We confirm the previously revised stereochemistry of spiroviolene by X-ray crystallographically characterizing a hydrazone derivative of 9-oxospiroviolane, which is synthesized by hydroboration/oxidation of spiroviolene followed by oxidation of the resultant hydroxy group. An unexpected thermal boron migration occurred during the hydroboration process of spiroviolene that resulted in the production
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Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-17 Kara A. Strickland, Brenda Martinez Rodriguez, Ashley A. Holland, Shelby Wagner, Michelle Luna-Alva, David E. Graham, Jonathan D. Caranto
Abstract Linear nitramines (R–N(R′)NO2; R′ = H or alkyl) are toxic compounds, some with environmental relevance, while others are rare natural product nitramines. One of these natural product nitramines is N-nitroglycine (NNG), which is produced by some Streptomyces strains and exhibits antibiotic activity towards Gram-negative bacteria. An NNG degrading heme enzyme, called NnlA, has recently been
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Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-16 Dongxu Zhang, Wenyu Du, Xingming Pan, Xiaoxu Lin, Fang-Ru Li, Qingling Wang, Qian Yang, Hui-Min Xu, Liao-Bin Dong
Abstract Drimane-type sesquiterpenoids (DMTs) are characterized by a distinctive 6/6 bicyclic skeleton comprising the A and B rings. While DMTs are commonly found in fungi and plants, their presence in bacteria has not been reported. Moreover, the biosynthetic pathways for DMTs have been primarily elucidated in fungi, with identified P450s only acting on the B ring. In this study, we isolated and characterized
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Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-16 Martyn Jevric, Julian Klepp, Johannes Puschnig, Oscar Lamb, Christopher J. Sumby, Ben W. Greatrex
Abstract A skeletal rearrangement of a series of 6,8-dioxabicyclo[3.2.1]octan-4-ols has been developed using SOCl2 in the presence of pyridine. An oxygen migration from C5 to C4 was observed when the C4 alcohols were treated with SOCl2/pyridine, giving a 2-chloro-3,8-dioxabicyclo[3.2.1]octane ring-system via the chlorosulfite intermediate. Analogous allylic alcohols with endocyclic and exocyclic unsaturations
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Advancements in hydrochlorination of alkenes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-15 Daniel S. Müller
Abstract The hydrochlorination of alkenes has been extensively studied in research and is commonly featured in organic chemistry textbooks as an exemplification of the Markovnikov rule. However, the application of this reaction is typically limited to specific alkenes, such as highly substituted ones, styrenes, or strained systems. Conversely, monosubstituted or 1,2-disubstituted alkenes do not readily
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Synthesis of new representatives of A3B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-12 Victoria M. Alpatova, Evgeny G. Rys, Elena G. Kononova, Valentina A. Ol'shevskaya
Abstract A carboranylporphyrin of A3B-type bearing a single pentafluorophenyl ring was prepared through the regioselective nucleophilic aromatic substitution reaction of the p-fluorine atoms in 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin with 9-mercapto-m-carborane. The reaction of this porphyrin with sodium azide led to the selective substitution of the p-fluorine atom in the pentafluorophenyl
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Synthesis and characterization of water-soluble C60–peptide conjugates Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-12 Yue Ma, Lorenzo Persi, Yoko Yamakoshi
Abstract With the aim of developing biocompatible and water-soluble C60 derivatives, three types of C60–peptide conjugates consisting of hydrophilic oligopeptide anchors (oligo-Lys, oligo-Glu, and oligo-Arg) were synthesized. A previously reported Prato reaction adduct of a biscarboxylic acid-substituted C60 derivative was subjected to a solid phase synthesis for amide formation with N-terminal amines
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Methodology for awakening the potential secondary metabolic capacity in actinomycetes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-10 Shun Saito, Midori A. Arai
Abstract Secondary metabolites produced by actinomycete strains undoubtedly have great potential for use in applied research areas such as drug discovery. However, it is becoming difficult to obtain novel compounds because of repeated isolation around the world. Therefore, a new strategy for discovering novel secondary metabolites is needed. Many researchers believe that actinomycetes have as yet unanalyzed
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Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-09 Zhongwei Hua, Nan Liu, Xiaohui Yan
Abstract Crocins are water-soluble apocarotenoids isolated from the flowers of crocus and gardenia. They exhibit various pharmacological effects, including neuroprotection, anti-inflammatory properties, hepatorenal protection, and anticancer activity. They are often used as coloring and seasoning agents. Due to the limited content of crocins in plants and the high cost of chemical synthesis, the supply
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Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-05 Zhiyong Yin, Jeroen S. Dickschat
Abstract An isotopic labelling method was developed to investigate substrate binding by ketosynthases, exemplified by the second ketosynthase of the polyketide synthase BaeJ involved in bacillaene biosynthesis (BaeJ-KS2). For this purpose, both enantiomers of a 13C-labelled N-acetylcysteamine thioester (SNAC ester) surrogate of the proposed natural intermediate of BaeJ-KS2 were synthesised, including
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Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-04 Senze Qiao, Zhongyu Cheng, Fuzhuo Li
Abstract Chemoenzymatic strategies that combine synthetic and enzymatic transformations offer efficient approaches to yield target molecules, which have been increasingly employed in the synthesis of bioactive natural products. In the biosynthesis of macrocyclic nonribosomal peptides, polyketides, and their hybrids, thioesterase (TE) domains play a significant role in late-stage macrocyclization. These
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SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-03 Julien Borrel, Jerome Waser
Abstract We report the detailed background for the discovery and development of the synthesis of homopropargylic azides by the azido-alkynylation of alkenes. Initially, a strategy involving SOMOphilic alkynes was adopted, but only resulted in a 29% yield of the desired product. By switching to a radical-polar crossover approach and after optimization, a high yield (72%) of the homopropargylic azide
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Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-03 Fumito Sato, Terutaka Sonohara, Shunta Fujiki, Akihiro Sugawara, Yohei Morishita, Taro Ozaki, Teigo Asai
Abstract Labdane-related diterpenoids (LRDs) in fungi are a pharmaceutically important, but underexplored family of natural products. In the biosynthesis of fungal LRDs, bifunctional terpene cyclases (TCs) consisting of αβγ domains are generally used to synthesize the polycyclic skeletones of LRDs. Herein, we conducted genome mining of LRDs in our fungal genome database and identified a unique pair
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Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-02 Jan Bartáček, Karel Chlumský, Jan Mrkvička, Lucie Paloušová, Miloš Sedlák, Pavel Drabina
Abstract The new chiral ligands I–III based on derivatives of imidazolidin-4-one were synthesised and characterised. The catalytic activity and enantioselectivity of their corresponding copper(II) complexes were studied in asymmetric Henry reactions. It was found that the enantioselectivity of these catalysts is overall very high and depends on the relative configuration of the ligand used; cis-configuration
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New variochelins from soil-isolated Variovorax sp. H002 Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-04-02 Jabal Rahmat Haedar, Aya Yoshimura, Toshiyuki Wakimoto
Abstract The soil bacterial genus Variovorax produce distinct photoreactive siderophores that may play a crucial role in the iron cycle within the rhizosphere. This study focused on exploring the natural products of the soil-isolated Variovorax sp. H002, leading to the isolation of variochelins A–E (1–5), a series of lipohexapeptide siderophores. NMR and MS/MS analyses revealed that these siderophores
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Organic electron transport materials Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-28 Joseph Cameron, Peter J. Skabara
Beilstein J. Org. Chem. 2024, 20, 672–674. doi:10.3762/bjoc.20.60
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Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-28 Dāgs Dāvis Līpiņš, Andris Jeminejs, Una Ušacka, Anatoly Mishnev, Māris Turks, Irina Novosjolova
Abstract 2-Chloro-4-sulfonylquinazolines undergo functional group swap when treated with an azide nucleophile: 1) the azide replaces the sulfonyl group at the C4 position; 2) the intrinsic azide–tetrazole tautomeric equilibrium directs the nucleofugal sulfinate from the first step to replace chloride at the C2 position. This transformation is effective with quinazolines bearing electron-rich substituents
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Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-27 Geng-Xin Liu, Xiao-Ting Jie, Ge-Jun Niu, Li-Sheng Yang, Xing-Lin Li, Jian Luo, Wen-Hao Hu
Abstract Herein, we report a visible-light-mediated palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines, affording unsaturated γ- and ε-amino acid derivatives with diverse structures. In this methodology, the diazo compound readily transforms into a hybrid α-ester alkylpalladium radical with the release of dinitrogen. The
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Enhanced reactivity of Li+@C60 toward thermal [2 + 2] cycloaddition by encapsulated Li+ Lewis acid Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-25 Hiroshi Ueno, Yu Yamazaki, Hiroshi Okada, Fuminori Misaizu, Ken Kokubo, Hidehiro Sakurai
Abstract Lithium ion-endohedral fullerene (Li+@C60), a member of the burgeoning family of ion-endohedral fullerenes, holds substantial promise for diverse applications owing to its distinctive ionic properties. Despite the high demand for precise property tuning through chemical modification, there have been only a few reports detailing synthetic protocols for the derivatization of this novel material
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Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-21 Kairi Umeda, Naoaki Kurisawa, Ghulam Jeelani, Tomoyoshi Nozaki, Kiyotake Suenaga, Arihiro Iwasaki
Abstract Polycavernoside E (1), a new polycavernoside analog, was isolated from a marine Okeania sp. cyanobacterium. The relative configuration was elucidated primarily by analyzing the two dimensional nuclear magnetism resonance (2D NMR) data. The absolute configuration was clarified by comparing the electronic circular dichroism (ECD) data of 1 with those of known analogs. Polycavernoside E (1) exhibited
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Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-20 Jia Tang, Yixiang Zhang, Yudai Matsuda
Abstract Fungal meroterpenoids are diverse structurally intriguing molecules with various biological properties. One large group within this compound class is derived from the aromatic precursor 3,5-dimethylorsellinic acid (DMOA). In this study, we constructed engineered metabolic pathways in the fungus Aspergillus oryzae to expand the molecular diversity of meroterpenoids. We employed the 5-methylorsellinic
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HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines Beilstein. J. Org. Chem. (IF 2.7) Pub Date : 2024-03-19 Luan A. Martinho, Carlos Kleber Z. Andrade
Abstract The imidazo[1,2-a]pyridine moiety is present in drugs with several biological activities. The most direct way of obtaining this nucleus is the Groebke–Blackburn–Bienaymé three-component reaction (GBB-3CR) between aminopyridines, aldehydes, and isocyanides under both Lewis and Brønsted acid catalysis. However, several catalysts for this reaction have major drawbacks such as being expensive
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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