Chemists around the globe are extensively working for remedial solutions to cancer, one of the greatest health hazards. We have synthesized twenty‐three novel spiro [chromane‐2,4′‐piperidin]‐ 4 ‐one derivatives (KBS and KMS series of analogues) as part of our ongoing research to combat this deadly disease, and confirmed their structures using 1H NMR, 13C NMR, HRMS, and FT‐IR. Furthermore, we employed single‐crystal XRD to identify the compound structures of KBS4 and KMS10. We have tested the compounds on the cell line such as MCF‐7; U87‐MG; SCC‐25; and HEK‐293T, via WST‐1 assay. Eight compounds showed IC50 values ranging 3.9–10 μM; against the cell line MCF‐7. The best compounds of all were KMS9 (IC50=3.83 μM), KMS5 (IC50=4.14 μM), and KBS8 (IC50=8.24 μM), which promoted apoptosis in MCF‐7 cells. KMS5 and KMS9 compounds showed G1 cell cycle arrest, while compound KBS8 showed G2 cell cycle arrest. Insilco ADME studies were carried out. Molecular docking and dynamics experiments showed how KMS5, KMS9, and KBS8 bind to the active region of the EGFR family – a group of receptor tyrosine kinase (RTK) proteins (PDB ID: 7JXP, 2.16 Å). Further structural modifications of the KMS5, KMS9, and KBS8 may improve their activity against breast cancer.
{"title":"Design and Synthesis of Novel Spiro [Chromane‐2,4′‐Piperidin]‐4‐One Derivatives: Anti‐Proliferative Investigation and Molecular Docking Studies","authors":"Srinuvasu Nakka , Suryansh Sengar , Kosana Sai Chaitanya , Swati , Ala Chandu , Murugesan Sankaranarayanan , Vivek Sharma , Nagaraju Devunuri , Kondapalli Venkata Gowri Chandra Sekhar","doi":"10.1002/ajoc.202400604","DOIUrl":"10.1002/ajoc.202400604","url":null,"abstract":"<div><div>Chemists around the globe are extensively working for remedial solutions to cancer, one of the greatest health hazards. We have synthesized twenty‐three novel spiro [chromane‐2,4′‐piperidin]‐ 4 ‐one derivatives (<strong>KBS</strong> and <strong>KMS</strong> series of analogues) as part of our ongoing research to combat this deadly disease, and confirmed their structures using <sup>1</sup>H NMR, <sup>13</sup>C NMR, HRMS, and FT‐IR. Furthermore, we employed single‐crystal XRD to identify the compound structures of <strong>KBS4</strong> and <strong>KMS10</strong>. We have tested the compounds on the cell line such as MCF‐7; U87‐MG; SCC‐25; and HEK‐293T, via WST‐1 assay. Eight compounds showed IC<sub>50</sub> values ranging 3.9–10 μM; against the cell line MCF‐7. The best compounds of all were <strong>KMS9</strong> (IC<sub>50</sub>=3.83 μM), <strong>KMS5</strong> (IC<sub>50</sub>=4.14 μM), and <strong>KBS8</strong> (IC<sub>50</sub>=8.24 μM), which promoted apoptosis in MCF‐7 cells. <strong>KMS5</strong> and <strong>KMS9</strong> compounds showed G1 cell cycle arrest, while compound <strong>KBS8</strong> showed G2 cell cycle arrest. Insilco ADME studies were carried out. Molecular docking and dynamics experiments showed how <strong>KMS5</strong>, <strong>KMS9</strong>, and <strong>KBS8</strong> bind to the active region of the <strong>EGFR</strong> family – a group of receptor tyrosine kinase (RTK) proteins <strong>(PDB ID: 7JXP, 2.16 Å)</strong>. Further structural modifications of the <strong>KMS5, KMS9</strong>, and <strong>KBS8</strong> may improve their activity against breast cancer.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400604"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424239","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}
Depsides are a class of natural products in which two or more (poly)phenolic acid derivatives are linked by an ester bond. Depsides and related natural products, such as depsidones and diphenyl ethers, are widespread in nature and exhibit a wide range of biological activities. Although their biosynthesis has attracted considerable research interest for many decades, it remained largely elusive until recently. Recent studies have revealed the molecular mechanisms underlying the biosynthesis of several depsides and related natural products, uncovering unique enzymatic chemistry in their biosynthetic pathways. This review summarizes the biosynthetic pathways and mechanisms for depsides, depsidones, and diphenyl ethers, focusing on fungi and lichens, which are the primary producers of these compounds.
{"title":"Biosynthesis of Depsides, Depsidones, and Diphenyl Ethers from Fungi and Lichens","authors":"Qiaolin Ji , Dr. Yudai Matsuda","doi":"10.1002/ajoc.202400451","DOIUrl":"10.1002/ajoc.202400451","url":null,"abstract":"<div><div>Depsides are a class of natural products in which two or more (poly)phenolic acid derivatives are linked by an ester bond. Depsides and related natural products, such as depsidones and diphenyl ethers, are widespread in nature and exhibit a wide range of biological activities. Although their biosynthesis has attracted considerable research interest for many decades, it remained largely elusive until recently. Recent studies have revealed the molecular mechanisms underlying the biosynthesis of several depsides and related natural products, uncovering unique enzymatic chemistry in their biosynthetic pathways. This review summarizes the biosynthetic pathways and mechanisms for depsides, depsidones, and diphenyl ethers, focusing on fungi and lichens, which are the primary producers of these compounds.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400451"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajoc.202400451","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424297","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}
Rajasekharan Jayakumari Deepak , Aswathi Ravindran N. E. , Ramasamy Karvembu
Ruthenium‐polyoxoniobate complexes were found to be efficient catalysts for the selective synthesis of 2‐substituted benzimidazoles and 1,2‐disubstituted benzimidazoles by solvent switching. The current strategy enables the synthesis of 2‐substituted benzimidazoles in water as a green solvent. Switching to aprotic solvents resulted in the formation of 1,2‐disubstituted benzimidazoles as the major product. Control experiments showed the involvement of both acceptorless dehydrogenative and oxidative coupling pathways. The method was extended to synthesize various 2‐substituted and 1,2‐disubstituted benzimidazole derivatives, and the desired products were obtained in moderate to good yields.
{"title":"Solvent Dependent Selectivity in the Synthesis of 1,2‐Disubstituted and 2‐Substituted Benzimidazoles by Dehydrogenative Coupling Reactions with Ruthenium‐Polyoxoniobate Catalysts","authors":"Rajasekharan Jayakumari Deepak , Aswathi Ravindran N. E. , Ramasamy Karvembu","doi":"10.1002/ajoc.202400575","DOIUrl":"10.1002/ajoc.202400575","url":null,"abstract":"<div><div>Ruthenium‐polyoxoniobate complexes were found to be efficient catalysts for the selective synthesis of 2‐substituted benzimidazoles and 1,2‐disubstituted benzimidazoles by solvent switching. The current strategy enables the synthesis of 2‐substituted benzimidazoles in water as a green solvent. Switching to aprotic solvents resulted in the formation of 1,2‐disubstituted benzimidazoles as the major product. Control experiments showed the involvement of both acceptorless dehydrogenative and oxidative coupling pathways. The method was extended to synthesize various 2‐substituted and 1,2‐disubstituted benzimidazole derivatives, and the desired products were obtained in moderate to good yields.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400575"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423659","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}
The stereoselective mechanochemical synthesis of Z‐enaminones and bis‐enaminones was achieved without any solid component in most cases, reacting 1,3‐dicarbonyl compounds with aliphatic/aromatic primary/secondary amines, which demonstrates the viability of reacting exclusively liquid reagents. The scale‐up was robust, from five to fifty and five hundred mmol without reduction in the reaction yield. The mechanochemical telescopic synthesis of β,γ‐unsaturated butyrolactams was achieved by formal [3+2] azaanulation reaction of intermediate enaminone with maleic anhydride, boosting the access of this potentially bioactive class of compound. The mechanochemical approach revealed its sustainable face in both syntheses, avoiding solid grinding auxiliary and purification by column chromatography. A symbol was suggested to differentiate the representation of the planetary ball mill from other mechanochemical reactors, wherein three spheres are surrounded by two curved arrows representing the two inherent movements of planetary trajectories of the reaction vessel of this equipment.
{"title":"Mechanosynthesis of Enaminones and Mechanochemical Telescopic Synthesis of β,γ‐unsaturated Butyrolactams","authors":"Edson Evangelista , Silvio Cunha","doi":"10.1002/ajoc.202400434","DOIUrl":"10.1002/ajoc.202400434","url":null,"abstract":"<div><div>The stereoselective mechanochemical synthesis of Z‐enaminones and bis‐enaminones was achieved without any solid component in most cases, reacting 1,3‐dicarbonyl compounds with aliphatic/aromatic primary/secondary amines, which demonstrates the viability of reacting exclusively liquid reagents. The scale‐up was robust, from five to fifty and five hundred mmol without reduction in the reaction yield. The mechanochemical telescopic synthesis of β,γ‐unsaturated butyrolactams was achieved by formal [3+2] azaanulation reaction of intermediate enaminone with maleic anhydride, boosting the access of this potentially bioactive class of compound. The mechanochemical approach revealed its sustainable face in both syntheses, avoiding solid grinding auxiliary and purification by column chromatography. A symbol was suggested to differentiate the representation of the planetary ball mill from other mechanochemical reactors, wherein three spheres are surrounded by two curved arrows representing the two inherent movements of planetary trajectories of the reaction vessel of this equipment.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400434"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424063","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}
A novel and practical zinc‐catalysed synthesis of 1H‐pyrazole has been developed. The one‐pot protocol enables the cycloaddition of enaminone and tosylhydrazide via C−N and S−N bond breaking process, leading to diverse mono‐substituted pyrazole derivatives in high yields. Moreover, the easily accessible materials, broad substrate scope with excellent functional group tolerance, ease of isolation and open‐air conditions are the key features of the present method.
{"title":"Zinc‐Catalysed (3+2) Cycloaddition of Enaminone with Tosylhydrazide to Synthesise 1H‐Pyrazole via C−N and S−N Bond Cleavage","authors":"Sanjukta Roy , Rana Chatterjee , Rambabu Dandela","doi":"10.1002/ajoc.202400549","DOIUrl":"10.1002/ajoc.202400549","url":null,"abstract":"<div><div>A novel and practical zinc‐catalysed synthesis of 1<em>H</em>‐pyrazole has been developed. The one‐pot protocol enables the cycloaddition of enaminone and tosylhydrazide via C−N and S−N bond breaking process, leading to diverse mono‐substituted pyrazole derivatives in high yields. Moreover, the easily accessible materials, broad substrate scope with excellent functional group tolerance, ease of isolation and open‐air conditions are the key features of the present method.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400549"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423880","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}
Hina Zaman , Aamer Saeed , Tamknat ul Muntaha , Hammad Ismail , Muhammad Rashid
In drug development, the 1,3‐thiazole‐2‐imines scaffolds are widely used to discern novel and potential therapies for the elimination of the most challenging diseases. The cyclopropyl motif is found in various medications such as antiviral drug Paxlovid, used to treat COVID‐19. Its presence enhances the metabolic stability and lipophilicity of drugs, making them more effective. Therefore, in the present work, we developed a library of novel cyclopropyl clubbed 1,3‐thiazole‐2‐imines (6 a–h) from the efficient cyclization between multistep synthesized thiourea precursors and ethyl 2‐chloroacetoacetate. Subsequently, the in vitro biological screening including antibacterial, α‐amylase, and proteinase K inhibition was carried out to assess their inhibition potential. In general, all synthesized compounds revealed moderate to significant potency. The compound (6 a) with no substitution at the phenyl ring exhibited the highest inhibitory activity amongst all, with an IC50 value of 1.716±0.062 μM against proteinase K. Fortunately, this compound (6 a) also unfolded the most significant antibacterial potential against B. subtilis showing 20 mm zone of inhibition. The compound (6 d) possessing a naphthyl ring was found to be the most potent inhibitor of amylase displaying IC50 value of 1.634±0.002 μM. Diverse substitution patterns on the framework of 1,3‐thiazole‐2‐imine pharmacophores provided a valuable basis for SAR analysis. Over and above, computational studies including DFT, molecular electrostatic potential, molecular docking, and ADMET were conducted to predict the chemical reactivity, ligand‐protein binding interactions, and drug‐likeness of synthesized compounds. Hence these studies highlighted our synthesized compounds as novel antibacterial, α‐amylase, and proteinase K inhibitors. Further research could be encouraged by modifying the substituents and their positions on the structure to attain the potent efficacy of these compounds.
{"title":"Novel Cyclopropyl Appended 1,3‐Thiazole‐2‐Imines as Multi‐Target Agents: Design, Synthesis, Biological Evaluation and Computational Studies","authors":"Hina Zaman , Aamer Saeed , Tamknat ul Muntaha , Hammad Ismail , Muhammad Rashid","doi":"10.1002/ajoc.202400598","DOIUrl":"10.1002/ajoc.202400598","url":null,"abstract":"<div><div>In drug development, the 1,3‐thiazole‐2‐imines scaffolds are widely used to discern novel and potential therapies for the elimination of the most challenging diseases. The cyclopropyl motif is found in various medications such as antiviral drug Paxlovid, used to treat COVID‐19. Its presence enhances the metabolic stability and lipophilicity of drugs, making them more effective. Therefore, in the present work, we developed a library of novel cyclopropyl clubbed 1,3‐thiazole‐2‐imines (<strong>6 a</strong>–<strong>h</strong>) from the efficient cyclization between multistep synthesized thiourea precursors and ethyl 2‐chloroacetoacetate. Subsequently, the <em>in vitro</em> biological screening including antibacterial, <em>α</em>‐amylase, and proteinase K inhibition was carried out to assess their inhibition potential. In general, all synthesized compounds revealed moderate to significant potency. The compound (<strong>6 a</strong>) with no substitution at the phenyl ring exhibited the highest inhibitory activity amongst all, with an IC<sub>50</sub> value of 1.716±0.062 μM against proteinase K. Fortunately, this compound (<strong>6 a</strong>) also unfolded the most significant antibacterial potential against <em>B. subtilis</em> showing 20 mm zone of inhibition. The compound (<strong>6 d</strong>) possessing a naphthyl ring was found to be the most potent inhibitor of amylase displaying IC<sub>50</sub> value of 1.634±0.002 μM. Diverse substitution patterns on the framework of 1,3‐thiazole‐2‐imine pharmacophores provided a valuable basis for SAR analysis. Over and above, computational studies including DFT, molecular electrostatic potential, molecular docking, and ADMET were conducted to predict the chemical reactivity, ligand‐protein binding interactions, and drug‐likeness of synthesized compounds. Hence these studies highlighted our synthesized compounds as novel antibacterial, <em>α</em>‐amylase, and proteinase K inhibitors. Further research could be encouraged by modifying the substituents and their positions on the structure to attain the potent efficacy of these compounds.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400598"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424238","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}
N‐heterocyclic carbene (NHC) catalyzed reactions of carboxylic acids play a crucial role in NHC catalysis, enabling the formation of chiral and achiral functional molecules. In this review, the achievements in NHC catalyzed activations of carboxylic acids are summarized, and an outlook on future research directions is also provided.
{"title":"N‐Heterocyclic Carbene Catalyzed Activation of Carboxylic Acids","authors":"Yueling Qin , Tingting Li","doi":"10.1002/ajoc.202400585","DOIUrl":"10.1002/ajoc.202400585","url":null,"abstract":"<div><div>N‐heterocyclic carbene (NHC) catalyzed reactions of carboxylic acids play a crucial role in NHC catalysis, enabling the formation of chiral and achiral functional molecules. In this review, the achievements in NHC catalyzed activations of carboxylic acids are summarized, and an outlook on future research directions is also provided.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400585"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424187","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}
Jing Li , Bao‐Sen Xu , Xinglong‐Zhang , Le‐Le Zhao , Shao‐Zhe Yi , Bao‐Ning Li
The optical materials based on excited state intramolecular proton transfer (ESIPT) have garnered significant attention due to their unique photophysical properties and applications in sensors and imaging agents (probes). These materials exhibit an intrinsic four‐level photocycle scheme through the enol (E)‐keto (K) phototautomerization process, resulting in a large Stokes shift, environmental sensitivity, and potential for ratiometric sensing. This review primarily focuses on elucidating the luminescence mechanism and structure‐property relationships of recent ESIPT molecules, as well as exploring the sensing applications of phosphorescent functional materials.
{"title":"Recent Advances in Smart Sensing Based on Excited‐State Intramolecular Proton‐Transfer (ESIPT)‐Inspired Emitters","authors":"Jing Li , Bao‐Sen Xu , Xinglong‐Zhang , Le‐Le Zhao , Shao‐Zhe Yi , Bao‐Ning Li","doi":"10.1002/ajoc.202400572","DOIUrl":"10.1002/ajoc.202400572","url":null,"abstract":"<div><div>The optical materials based on excited state intramolecular proton transfer (ESIPT) have garnered significant attention due to their unique photophysical properties and applications in sensors and imaging agents (probes). These materials exhibit an intrinsic four‐level photocycle scheme through the enol (E)‐keto (K) phototautomerization process, resulting in a large Stokes shift, environmental sensitivity, and potential for ratiometric sensing. This review primarily focuses on elucidating the luminescence mechanism and structure‐property relationships of recent ESIPT molecules, as well as exploring the sensing applications of phosphorescent functional materials.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400572"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424322","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}
Two covalently linked fluorescent tetrads containing two BODIPY units and two 3‐pyrrolyl BODIPY units have been synthesized over a sequence of steps starting with bis(3‐pyrrolyl BODIPY) as the key precursor. Both covalently linked tetrads 6 and 7 were confirmed by HR‐MS and characterized and studied by 1D and 2D NMR, absorption, cyclic voltammetry, steady state and time‐resolved fluorescence techniques, and also by DFT and TD‐DFT methods. The tetrad 6 exhibited one strong absorption band at 680 nm whereas the tetrad 7 showed strong absorption bands at 510 nm and 648 nm corresponding to BODIPY and 3‐pyrrolyl BODIPY units respectively and the absorption band of tetrad 6 was bathochromically shifted due to effective π‐conjugation in tetrad 6 compared to tetrad 7. The electrochemical studies revealed that tetrads exhibit only two reductions indicating their electron deficient nature. The steady state and time‐resolved fluorescence studies invoked a possibility of singlet‐singlet energy transfer from BODIPY units to 3‐pyrrolyl BODIPY units in one of the tetrads upon selective excitation of BODIPY unit. In this tetrad, the BODIPY unit acts as an energy donor whereas the 3‐pyrrolyl BODIPY unit acts as an energy acceptor. The theoretical studies were corroborated with experimental results. Group webpage: https://ravikanthlab.wixsite.com/mysite/.
{"title":"Synthesis and Properties of Covalently Linked Fluorescent Tetrads Containing Two BODIPYs and Two 3‐Pyrrolyl BODIPYs","authors":"Pinky Chauhan , Prof. Mangalampalli Ravikanth","doi":"10.1002/ajoc.202400551","DOIUrl":"10.1002/ajoc.202400551","url":null,"abstract":"<div><div>Two covalently linked fluorescent tetrads containing two BODIPY units and two 3‐pyrrolyl BODIPY units have been synthesized over a sequence of steps starting with bis(3‐pyrrolyl BODIPY) as the key precursor. Both covalently linked tetrads <strong>6</strong> and <strong>7</strong> were confirmed by HR‐MS and characterized and studied by 1D and 2D NMR, absorption, cyclic voltammetry, steady state and time‐resolved fluorescence techniques, and also by DFT and TD‐DFT methods. The tetrad <strong>6</strong> exhibited one strong absorption band at 680 nm whereas the tetrad <strong>7</strong> showed strong absorption bands at 510 nm and 648 nm corresponding to BODIPY and 3‐pyrrolyl BODIPY units respectively and the absorption band of tetrad <strong>6</strong> was bathochromically shifted due to effective π‐conjugation in tetrad <strong>6</strong> compared to tetrad <strong>7</strong>. The electrochemical studies revealed that tetrads exhibit only two reductions indicating their electron deficient nature. The steady state and time‐resolved fluorescence studies invoked a possibility of singlet‐singlet energy transfer from BODIPY units to 3‐pyrrolyl BODIPY units in one of the tetrads upon selective excitation of BODIPY unit. In this tetrad, the BODIPY unit acts as an energy donor whereas the 3‐pyrrolyl BODIPY unit acts as an energy acceptor. The theoretical studies were corroborated with experimental results. Group webpage: <span><span>https://ravikanthlab.wixsite.com/mysite/</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400551"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423881","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}
Dr. Tomohiro Umeno , Mio Tanaka , Moeka Fujihara , Naoko Iizuka , Shota Matsumoto , Dr. Kazuteru Usui , Prof. Satoru Karasawa
Guanidine is strongly basic and has a high molecular recognition ability. We previously developed a guanidine‐bearing benzoquinoline for the fluorescence detection of MeOH by exploiting the strong basicity of guanidine. The benzoquinoline fluorophore quantitatively detected MeOH in EtOH with moderate sensitivity and a limit of detection (LOD) of 16.5 %. In this study, we developed two guanidinyl boron dipyrromethene (BODIPY) and two guanidinyl coumarin fluorophores. These fluorophores have higher molar extinction coefficients (ϵ) than those of benzoquinolines, which suggests that they could have improved detection sensitivity. The BODIPY fluorophores exhibited acid‐responsive turn‐on fluorescence for MeOH, similar to the benzoquinoline fluorophore. Their high ϵ values led to an enhanced MeOH detection sensitivity of 1.3 % in EtOH. The coumarin derivatives exhibited acid‐responsive turn‐off fluorescence. In addition, the absorbance spectral shift of the protonated and neutral forms of coumarin enabled the ratiometric detection of MeOH (LOD=0.85 % and 0.57 %, respectively). This study demonstrates the utility of guanidine‐based fluorophores in molecular recognition and promotes the development of similar fluorophores in analytical chemistry.
{"title":"Advanced pH Indicators Consisting of BODIPY and Coumarin Fluorophores with a Guanidinyl Structure Capable of Methanol Recognition","authors":"Dr. Tomohiro Umeno , Mio Tanaka , Moeka Fujihara , Naoko Iizuka , Shota Matsumoto , Dr. Kazuteru Usui , Prof. Satoru Karasawa","doi":"10.1002/ajoc.202400605","DOIUrl":"10.1002/ajoc.202400605","url":null,"abstract":"<div><div>Guanidine is strongly basic and has a high molecular recognition ability. We previously developed a guanidine‐bearing benzoquinoline for the fluorescence detection of MeOH by exploiting the strong basicity of guanidine. The benzoquinoline fluorophore quantitatively detected MeOH in EtOH with moderate sensitivity and a limit of detection (LOD) of 16.5 %. In this study, we developed two guanidinyl boron dipyrromethene (BODIPY) and two guanidinyl coumarin fluorophores. These fluorophores have higher molar extinction coefficients (ϵ) than those of benzoquinolines, which suggests that they could have improved detection sensitivity. The BODIPY fluorophores exhibited acid‐responsive turn‐on fluorescence for MeOH, similar to the benzoquinoline fluorophore. Their high ϵ values led to an enhanced MeOH detection sensitivity of 1.3 % in EtOH. The coumarin derivatives exhibited acid‐responsive turn‐off fluorescence. In addition, the absorbance spectral shift of the protonated and neutral forms of coumarin enabled the ratiometric detection of MeOH (LOD=0.85 % and 0.57 %, respectively). This study demonstrates the utility of guanidine‐based fluorophores in molecular recognition and promotes the development of similar fluorophores in analytical chemistry.</div></div>","PeriodicalId":130,"journal":{"name":"Asian Journal of Organic Chemistry","volume":"14 2","pages":"Article e202400605"},"PeriodicalIF":2.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424257","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号