Beilstein Journal of Organic Chemistry最新文献_第10页

pKalculator: A pKa predictor for C–H bonds pKalculator：C-H 键的 pKa 预测器

IF 2.2 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-16 DOI: 10.3762/bjoc.20.144

Rasmus M Borup, Nicolai Ree, Jan H Jensen

引用次数: 0

Divergent role of PIDA and PIFA in the AlX3 (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study PIDA 和 PIFA 在 AlX3（X = Cl、Br）卤化 2-萘酚中的不同作用：一项机理研究

IF 2.2 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-15 DOI: 10.3762/bjoc.20.141

Kevin A. Juarez-Ornelas, Manuel Solís-Hernández, P. Navarro‐Santos, J. Jiménez-Halla, C. Solorio-Alvarado

{"title":"Divergent role of PIDA and PIFA in the AlX3 (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study","authors":"Kevin A. Juarez-Ornelas, Manuel Solís-Hernández, P. Navarro‐Santos, J. Jiménez-Halla, C. Solorio-Alvarado","doi":"10.3762/bjoc.20.141","DOIUrl":"https://doi.org/10.3762/bjoc.20.141","url":null,"abstract":"The reaction mechanism for the chlorination and bromination of 2-naphthol with PIDA or PIFA and AlX3 (X = Cl, Br), previously reported by our group, was elucidated via quantum chemical calculations using density functional theory. The chlorination mechanism using PIFA and AlCl3 demonstrated a better experimental and theoretical yield compared to using PIDA. Additionally, the lowest-energy chlorinating species was characterized by an equilibrium of Cl–I(Ph)–OTFA–AlCl3 and [Cl–I(Ph)][OTFA–AlCl3], rather than PhICl2 being the active species. On the other hand, bromination using PIDA and AlBr3 was more efficient, wherein the intermediate Br–I(Ph)–OAc–AlBr3 was formed as active brominating species. Similarly, PhIBr2 was higher in energy than our proposed species. The reaction mechanisms are described in detail in this work and were found to be in excellent agreement with the experimental yield. These initial results confirmed that our proposed mechanism was energetically favored and therefore more plausible compared to halogenation via PhIX2.","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds 作为宏观软支架的两亲供体-受体斯登豪斯加合物超分子组装体

IF 2.2 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-15 DOI: 10.3762/bjoc.20.142

Ka-Lung Hung, Leong-Hung Cheung, Yikun Ren, Ming-Hin Chau, Yan-Yi Lam, Takashi Kajitani, Franco King‐Chi Leung

{"title":"Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds","authors":"Ka-Lung Hung, Leong-Hung Cheung, Yikun Ren, Ming-Hin Chau, Yan-Yi Lam, Takashi Kajitani, Franco King‐Chi Leung","doi":"10.3762/bjoc.20.142","DOIUrl":"https://doi.org/10.3762/bjoc.20.142","url":null,"abstract":"In the design of photoharvesting and photoresponsive supramolecular systems in aqueous medium, the fabrication of amphiphilic photoswitches enables a noninvasive functional response through photoirradiation. Although most aqueous supramolecular assemblies are driven by high-energy and biodamaging UV light, we have previously reported a design of amphiphilic donor–acceptor Stenhouse adducts (DASAs) controlled by white light. Herein, we present a series of DASA amphiphiles (DAs) with minor structural modifications on the alkyl linker chain length connecting the DASA motif with the hydrophilic moiety. The excellent photoswitchability in organic medium and the photoresponsiveness in aqueous medium, driven by visible light, were investigated by UV–vis absorption spectroscopy. The assembled supramolecular nanostructures were confirmed by electron microscopy, while the supramolecular packing was revealed by X-ray diffraction analysis. Upon visible-light irradiation, significant transformations of the DA geometry enabled transformations of the supramolecular assemblies on a microscopic scale, subsequently disassembling macroscopic soft scaffolds of DAs. The current work shows promising use for the fabrication of visible-light-controlled macroscopic scaffolds, offering the next generation of biomedical materials with visible-light-controlled microenvironments and future soft-robotic systems.","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines 二氟化吡咯烷中的同分异构效应和高切效应诱导的区域和立体化学稳定性

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-12 DOI: 10.3762/bjoc.20.140

Ana Flávia Candida Silva, Francisco A. Martins, Matheus P. Freitas

{"title":"Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines","authors":"Ana Flávia Candida Silva, Francisco A. Martins, Matheus P. Freitas","doi":"10.3762/bjoc.20.140","DOIUrl":"https://doi.org/10.3762/bjoc.20.140","url":null,"abstract":"Abstract\u0000Selective fluorination of the pyrrolidine ring in proline motifs has been found to induce significant conformational changes that impact the structure and biological roles of modified peptides and proteins. Vicinal difluorination of fluoroproline, for example, in (3S,4R)-3,4-difluoroproline, serves to mitigate the inherent conformational bias of the pyrrolidine ring by inducing stereoelectronic effects that attenuate this conformational bias. In this investigation, we present a quantumchemical analysis of the conformational equilibrium and effects that are induced in difluorinated pyrrolidines, with a particular focus on exploring the impact of gauche and anomeric effects on the conformer stabilities of different stereo- and regioisomers. Initially, we conducted a benchmark assessment comparing the optimal density functional theory method with coupled cluster with single and double excitations (CCSD) calculations and crystallographic data using the 3-fluoropyrrolidinium cation and 3-fluoropyrrolidine. Subsequently, we explored the relative energy of all favored conformations of all different stereoisomers of 2,3-, 2,4-, and 3,4-difluoropyrrolidines at the B3LYP-D3BJ/6-311++G** level. A generalized anomeric effect, arising from nN→σ*CF electron delocalization, is particularly important in modulating the energetics of the α-fluoro isomers and imparts a strong conformational bias. In contrast, the fluorine gauche effect assumes a secondary role, as it is overshadowed by steric and electrostatic interactions, referred to as Lewis interactions from a natural bond orbital perspective.\u0000<img src='https://www.beilstein-journals.org/bjoc/content/figures/1860-5397-20-140-graphical-abstract.png?max-width=550' border='0'/>\u0000Beilstein J. Org. Chem. 2024, 20, 1572–1579. doi:10.3762/bjoc.20.140","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor 利用质子交换膜反应器在温和条件下对氰基烯烃、硝基烯烃、喹啉和吡啶进行电催化加氢反应

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-11 DOI: 10.3762/bjoc.20.139

Koichi Mitsudo, Atsushi Osaki, Haruka Inoue, Eisuke Sato, Naoki Shida, Mahito Atobe, Seiji Suga

引用次数: 0

Mining raw plant transcriptomic data for new cyclopeptide alkaloids 从原始植物转录组数据中挖掘新的环肽生物碱

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-11 DOI: 10.3762/bjoc.20.138

Draco Kriger, Michael A. Pasquale, Brigitte G. Ampolini, Jonathan R. Chekan

{"title":"Mining raw plant transcriptomic data for new cyclopeptide alkaloids","authors":"Draco Kriger, Michael A. Pasquale, Brigitte G. Ampolini, Jonathan R. Chekan","doi":"10.3762/bjoc.20.138","DOIUrl":"https://doi.org/10.3762/bjoc.20.138","url":null,"abstract":"Abstract\u0000In recent years, genome and transcriptome mining have dramatically expanded the rate of discovering diverse natural products from bacteria and fungi. In plants, this approach is often more limited due to the lack of available annotated genomes and transcriptomes combined with a less consistent clustering of biosynthetic genes. The recently identified burpitide class of ribosomally synthesized and post-translationally modified peptide (RiPP) natural products offer a valuable opportunity for bioinformatics-guided discovery in plants due to their short biosynthetic pathways and gene encoded substrates. Using a high-throughput approach to assemble and analyze 700 publicly available raw transcriptomic data sets, we uncover the potential distribution of split burpitide precursor peptides in Streptophyta. Metabolomic analysis of target plants confirms our bioinformatic predictions of new cyclopeptide alkaloids from both known and new sources.\u0000<img src='https://www.beilstein-journals.org/bjoc/content/figures/1860-5397-20-138-graphical-abstract.jpg?max-width=550' border='0'/>\u0000Beilstein J. Org. Chem. 2024, 20, 1548–1559. doi:10.3762/bjoc.20.138","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Benzylic C(sp3)–H fluorination 苄基 C（sp3）-H 氟化

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-10 DOI: 10.3762/bjoc.20.137

Alexander P. Atkins, Alice C. Dean, Alastair J. J. Lennox

引用次数: 0

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones 伯胺催化的吡唑啉-5-酮与α,β-不饱和酮的 1,4-迈克尔对映选择性加成反应

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-09 DOI: 10.3762/bjoc.20.136

Pooja Goyal, Akhil K. Dubey, Raghunath Chowdhury, Amey Wadawale

引用次数: 0

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide 叠氮化钠催化四丁基碘化铵对β-酮羰基化合物的氧化α-叠氮反应

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-05 DOI: 10.3762/bjoc.20.135

Christopher Mairhofer, David Naderer, Mario Waser

引用次数: 0

Towards an asymmetric β-selective addition of azlactones to allenoates 实现氮内酯与烯酸酯的不对称 β 选择性加成反应

IF 2.7 4区化学

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-04 DOI: 10.3762/bjoc.20.134

Behzad Nasiri, Ghaffar Pasdar, Paul Zebrowski, Katharina Röser, David Naderer, Mario Waser

引用次数: 0