Meng Qiu, Jing Du, Nai-Te Yao, Xin-Yue Wang, Han-Yuan Gong
{"title":"Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications.","authors":"Meng Qiu, Jing Du, Nai-Te Yao, Xin-Yue Wang, Han-Yuan Gong","doi":"10.3762/bjoc.21.106","DOIUrl":"https://doi.org/10.3762/bjoc.21.106","url":null,"abstract":"<p><p>Helicenes, a class of non-planar polycyclic aromatic hydrocarbons composed of <i>ortho</i>-fused aromatic rings forming helical architectures, have attracted considerable attention due to their intrinsic chirality and tunable optoelectronic properties. Among them, nitrogen-doped helicenes (azahelicenes) and their heteroatom-co-doped counterparts - such as B/N-, O/N-, S/N-, and Se/N-doped helicenes - have emerged as highly versatile scaffolds for chiral optoelectronic applications. The incorporation of nitrogen enables precise modulation of electronic structures, redox characteristics, and intermolecular interactions, thereby enhancing performance in circularly polarized luminescence (CPL), thermally activated delayed fluorescence (TADF), and chiral sensing. Notably, recent developments have yielded π-extended, structurally robust, and stimuli-responsive azahelicenes exhibiting record-high dissymmetry factors (|<i>g</i> <sub>abs</sub>| and |<i>g</i> <sub>lum</sub>|), elevated CPL brightness (<i>B</i> <sub>CPL</sub>), and efficient integration into CPL-OLEDs and redox-switchable emitters. Boron-nitrogen co-doping strategies, in particular, have facilitated the development of materials with ultra-narrowband emissions, near-unity photoluminescence quantum yields, and electroluminescence dissymmetry factors (|<i>g</i> <sub>EL</sub>|) exceeding 10<sup>-3</sup>. Likewise, heteroatom co-doping with oxygen, sulfur, or selenium enables spectral tuning across the visible to near-infrared range, improved photostability, and dual-state emissive behavior. In parallel, significant progress in synthetic methodologies - including enantioselective catalysis, electrochemical cyclizations, and multicomponent reaction systems - has granted access to increasingly complex helicene frameworks with well-defined chirality. This review systematically summarizes recent advancements in the synthesis, structural engineering, and chiroptical performance of nitrogen-doped helicenes and their heteroatom-doped derivatives, emphasizing their potential as next-generation chiral optoelectronic materials and outlining future directions toward multifunctional integration and quantum technological applications.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1422-1453"},"PeriodicalIF":2.2,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12256785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144636065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lidia Zaharieva, Vera Deneva, Fadhil S Kamounah, Nikolay Vassilev, Ivan Angelov, Michael Pittelkow, Liudmil Antonov
{"title":"Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds.","authors":"Lidia Zaharieva, Vera Deneva, Fadhil S Kamounah, Nikolay Vassilev, Ivan Angelov, Michael Pittelkow, Liudmil Antonov","doi":"10.3762/bjoc.21.105","DOIUrl":"https://doi.org/10.3762/bjoc.21.105","url":null,"abstract":"<p><p>Tautomerism in two new azo dyes, based on 7-hydroxyquinoline, has been considered from the viewpoint of the proton crane concept. Although 8-(phenyldiazenyl)quinolin-7-ol exists in solution as a mixture of azo and two hydrazone tautomers, as shown by the experimental and theoretical results, upon irradiation switching, based on long-range proton transfer, occurs in a limited extent. 8-(4-Hydroxy-1,2,3,5-tetrafluorophenyldiazenyl)quinolin-7-ol exists as a single enol (azo) tautomer and the reduced basicity of the azo group nitrogen atoms does not allow shift of the tautomeric state neither upon changing the solvent, nor upon irradiation. Possibilities for molecular design, allowing to improve the capacity of 7-hydroxy-8-(azophenyl)quinolines, are considered in terms of stabilization of the azo tautomer and making possible long range proton transfer to the quinolyl nitrogen atom.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1404-1421"},"PeriodicalIF":2.2,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12256787/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144636067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vladimir G Ilkin, Pavel S Silaichev, Valeriy O Filimonov, Tetyana V Beryozkina, Margarita D Likhacheva, Pavel A Slepukhin, Wim Dehaen, Vasiliy A Bakulev
{"title":"Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of <i>N</i>-sulfonyl-2,3-dihydro-1,2-thiazoles.","authors":"Vladimir G Ilkin, Pavel S Silaichev, Valeriy O Filimonov, Tetyana V Beryozkina, Margarita D Likhacheva, Pavel A Slepukhin, Wim Dehaen, Vasiliy A Bakulev","doi":"10.3762/bjoc.21.104","DOIUrl":"https://doi.org/10.3762/bjoc.21.104","url":null,"abstract":"<p><p>A one-step method has been developed for the preparation of 2,3-dihydro-2-sulfonyl-3,4,5-substituted 1,2-thiazoles by the reaction of acryl thioamides and iminoiodinanes. A library of 31 examples of tetrasubstituted 1,2-thiazoles was thus synthesized in high yields. The effectiveness of the synthesis method for these poorly studied 1,2-thiazoles was confirmed by scaling the reaction using gram amounts of the starting thioamide.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1397-1403"},"PeriodicalIF":2.2,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12256786/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144636066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joy E Rajakulendran, Emmanuel Tope Oluwabusola, Michela Cerone, Terry K Smith, Olusoji O Adebisi, Adefolalu Adedotun, Gagan Preet, Sylvia Soldatou, Hai Deng, Rainer Ebel, Marcel Jaspars
{"title":"<i>N</i>-Salicyl-amino acid derivatives with antiparasitic activity from <i>Pseudomonas</i> sp. UIAU-6B.","authors":"Joy E Rajakulendran, Emmanuel Tope Oluwabusola, Michela Cerone, Terry K Smith, Olusoji O Adebisi, Adefolalu Adedotun, Gagan Preet, Sylvia Soldatou, Hai Deng, Rainer Ebel, Marcel Jaspars","doi":"10.3762/bjoc.21.103","DOIUrl":"10.3762/bjoc.21.103","url":null,"abstract":"<p><p>Pseudomonads strains represent a promising source of bioactive compounds with potential pharmaceutical applications. The necessity to find new drugs is underscored by the increased concern over antimicrobial resistance in the human system. In this study, we isolated two previously undescribed <i>N</i>-salicyl-amino acids as natural products (<b>1</b> and <b>2</b>) and other two new derivatives (<b>3</b> and <b>4</b>) from the organic extract of a culture broth in a modified starch-glucose-glycerol (SGG) medium of <i>Pseudomonas</i> sp. UIAU-6B. The structure of the new natural products, pseudomonins D-G (<b>1</b>-<b>4</b>) isolated alongside other three known compounds, pseudomonine (<b>5</b>), pseudomonin B (<b>6</b>) and salicylic acid (<b>7</b>), were elucidated based on high-resolution mass spectrometry, 1D and 2D NMR analyses. The absolute configurations of the threonine residue in compounds <b>1</b> and <b>2</b> were determined by Marfey's analysis. Compound <b>4</b> displayed a very weak pan-trypanocidal activity against <i>Trypanosoma brucei, Trypanosoma cruzi and Leishmania major</i> with EC<sub>50</sub> values of 101-137 μM, while compounds <b>2</b> and <b>5</b> showed modest activity against <i>Leishmania major,</i> but none of the remaining compounds showed activity at the highest concentrations tested. The plausible biosynthetic hypotheses toward the compounds were also proposed.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1388-1396"},"PeriodicalIF":2.2,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12230329/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144582944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kelsey Plasse, Valerie Wright, Guoshu Xie, R Bernadett Vlocskó, Alexander Lazarev, Béla Török
{"title":"High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters.","authors":"Kelsey Plasse, Valerie Wright, Guoshu Xie, R Bernadett Vlocskó, Alexander Lazarev, Béla Török","doi":"10.3762/bjoc.21.102","DOIUrl":"10.3762/bjoc.21.102","url":null,"abstract":"<p><p>High hydrostatic pressure (HHP) was found to be an efficient activation method in several catalyst- and solvent-free reactions and has found application for the syntheses of heterocycles and the preparation of active pharmaceutical ingredients (APIs) via acylation and acid- and solvent-free esterification. The reactions were carried out at ambient pressure (control) and under HHP (up to 3.8 kbar) conditions. These representative reactions provided higher yields for the products and HHP enabled truly green processes that are catalyst- and solvent-free, to occur with high yields and producing only non-toxic by-products. A computational study accompanies the experimental data to interpret the outcome of the reactions.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1374-1387"},"PeriodicalIF":2.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12230333/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144582945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Oxetanes: formation, reactivity and total syntheses of natural products.","authors":"Peter Gabko, Martin Kalník, Maroš Bella","doi":"10.3762/bjoc.21.101","DOIUrl":"10.3762/bjoc.21.101","url":null,"abstract":"<p><p>Oxetanes are 4-membered cyclic monoethers which have found important applications in medicinal chemistry as polar and metabolically stable isosteric replacements for <i>gem</i>-dimethyl and carbonyl groups. This work reviews possible synthetic strategies towards these strained heterocycles, covering both de novo constructions of the 4-membered ring as well as derivatisations of oxetane building blocks, then reactivity of oxetanes in terms of ring-opening and ring-expansion reactions, and finally total syntheses of selected oxetane-containing natural products. The literature review primarily covers reports made after the year 2015, but a few older contributions that were considered relevant are also discussed.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1324-1373"},"PeriodicalIF":2.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207814/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao-Sen Wang, Lin Li, Xin Chen, Jian-Li Wu, Kai Sun, Xiao-Lan Chen, Ling-Bo Qu, Bing Yu
{"title":"Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer.","authors":"Hao-Sen Wang, Lin Li, Xin Chen, Jian-Li Wu, Kai Sun, Xiao-Lan Chen, Ling-Bo Qu, Bing Yu","doi":"10.3762/bjoc.21.100","DOIUrl":"10.3762/bjoc.21.100","url":null,"abstract":"<p><p>In recent years, amidyl radicals have emerged as highly efficient and versatile reagents for hydrogen atom transfer (HAT) in photocatalytic reactions. These radicals display exceptional selectivity and efficiency in abstracting hydrogen atoms from C-H, Si-H, B-H, and Ge-H, positioning them as invaluable tools in synthetic chemistry. This review summarizes the latest advancements in the photocatalyzed generation of amidyl radicals as HAT reagents, with a particular emphasis on their role in the intermolecular HAT process. We highlight key developments, mechanistic insights, and emerging strategies that harness the unique reactivity of amidyl radicals in the selective functionalization of a variety of substrates.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1306-1323"},"PeriodicalIF":2.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes.","authors":"Bartłomiej Pigulski","doi":"10.3762/bjoc.21.99","DOIUrl":"10.3762/bjoc.21.99","url":null,"abstract":"<p><p>In recent years, significant progress has been made in the synthesis of various nanographenes incorporating non-benzenoid rings, expanding the scope of molecular design beyond all-hexagon polycyclic aromatic hydrocarbons (PAHs). Among these, π-conjugated scaffolds featuring embedded azulene units have gained considerable attention due to their unique optical and electronic properties. This review provides an overview of representative azulene-embedded nanographenes, with a particular focus on the synthetic strategies. Additionally, it explores selected aspects of aromaticity and spectroscopic properties.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1272-1305"},"PeriodicalIF":2.2,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207812/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent advances in oxidative radical difunctionalization of <i>N</i>-arylacrylamides enabled by carbon radical reagents.","authors":"Jiangfei Chen, Yi-Lin Qu, Ming Yuan, Xiang-Mei Wu, Heng-Pei Jiang, Ying Fu, Shengrong Guo","doi":"10.3762/bjoc.21.98","DOIUrl":"10.3762/bjoc.21.98","url":null,"abstract":"<p><p>The field of radical-mediated functionalization of <i>N</i>-arylacrylamides has experienced considerable advancements in recent years, particularly in the domain of oxidative radical difunctionalization reactions employing carbon radical reagents. This approach provides a powerful and versatile strategy for the concurrent introduction of two distinct functional groups across the double bond of <i>N</i>-arylacrylamides, facilitating the rapid construction of complex molecular architectures. This review aims to summarize the diverse strategies for inducing intramolecular transformations of <i>N</i>-arylacrylamides using various carbon radical reagents, including methods initiated by photonic, thermal, or electrochemical processes, which have been extensively investigated by researchers.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1207-1271"},"PeriodicalIF":2.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207826/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander S Budnikov, Igor B Krylov, Fedor K Monin, Valentina M Merkulova, Alexey I Ilovaisky, Liu Yan, Bing Yu, Alexander O Terent'ev
{"title":"Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates.","authors":"Alexander S Budnikov, Igor B Krylov, Fedor K Monin, Valentina M Merkulova, Alexey I Ilovaisky, Liu Yan, Bing Yu, Alexander O Terent'ev","doi":"10.3762/bjoc.21.96","DOIUrl":"10.3762/bjoc.21.96","url":null,"abstract":"<p><p>Aerobic copper(II)-mediated phosphorylation of enol acetates with H-phosphonates leading to the formation of β-ketophosphonates was discovered. The proposed method is applicable to a wide range of H-phosphonates or phosphine oxides as PH-reagents and enol acetates. Unlike previous reports, which generally employed stoichiometric amounts of oxidants or more expensive transition metal catalysts, the present protocol employs only cheap copper sulfate pentahydrate as a catalyst under mild reaction conditions. The achieved phosphorylation proceeds via the formation of P-centered radicals produced by the oxidation of PH-reagents by copper(II)-containing species. Employing anhydrous CuSO<sub>4</sub> instead of the pentahydrate led to a dramatic phosphorylation yield drop from 70 to <5%. It seems that the ligand environment of copper is very important for the effective reaction: other Cu(II) and Cu(I) salts, including halides, nitrate, tetrafluoroborate, or perchlorate, were much less effective or completely inert.</p>","PeriodicalId":8756,"journal":{"name":"Beilstein Journal of Organic Chemistry","volume":"21 ","pages":"1192-1200"},"PeriodicalIF":2.2,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207267/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}