A rhenium-catalyzed, highly efficient, regio- and stereoselective hydrocarboxylation of internal alkynes and olefins has been developed. This simple, atom- and step-economic strategy provides facile access to functionalized aryl enol esters in high yields. Notably, several NSAID drug molecules (e.g., oxaprozin, ibuprofen, indomethacin, ketoprofen, naproxen, flurbiprofen, etc.) underwent hydrocarboxylation without the need for pre-functionalization. Deuterium-labeling studies revealed that proton transfer originates from the COOH group, while O–H bond cleavage is unlikely to be involved in the turnover-determining transition state (TDTS) of the catalytic cycle.
{"title":"Rhenium Catalyzed Stereoselective Hydrocarboxylation of Alkynes and Olefins: Late-Stage NSAID Drug’s Diversification","authors":"Suman Bhowmick, Mayank Singh, Khushboo Tiwari, Dharmendra Kumar Tiwari","doi":"10.1039/d5qo01612f","DOIUrl":"https://doi.org/10.1039/d5qo01612f","url":null,"abstract":"A rhenium-catalyzed, highly efficient, regio- and stereoselective hydrocarboxylation of internal alkynes and olefins has been developed. This simple, atom- and step-economic strategy provides facile access to functionalized aryl enol esters in high yields. Notably, several NSAID drug molecules (e.g., oxaprozin, ibuprofen, indomethacin, ketoprofen, naproxen, flurbiprofen, etc.) underwent hydrocarboxylation without the need for pre-functionalization. Deuterium-labeling studies revealed that proton transfer originates from the COOH group, while O–H bond cleavage is unlikely to be involved in the turnover-determining transition state (TDTS) of the catalytic cycle.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"8 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146223001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a covalently linked, electroactive, conformationally flexible naphthalene diimide (NDI) pentamer exhibiting unprecedented 10-electron reduction, solvent-dependent folding, and guest-induced tunable charge-transfer (CT). In dichloromethane and chloroform, the oligomer adopts a partially folded state, displaying bright excimer emission at 500 nm. The addition of methyl cyclohexane promotes ordered, long-range folding, thereby enhancing excimer emission. Conversely, the addition of toluene causes folding but quenches the excimer emission while inducing a distinct CT emission. Furthermore, various polyaromatic donors such as anthracene, triphenylene, pyrene, perylene, etc., promote folding by intercalating between NDI layers, forming a long-range alternate donor-acceptor stack with tunable CT absorption. The estimation of the association constant (Ka) revealed that the strength of CT complexation depends on the donor ability of the guests, with perylene showing the highest association constant. Interestingly, sequential addition of two different donors produces dual CT bands, resulting in broad visible light absorption. This study demonstrates a rare example of guest-dependent tunable CT-driven folding of a flexible multidecker NDI system, offering new insights into the guest-mediated conformational control of foldamer, and an approach towards ordered π-stacked materials.
{"title":"Guest-dependent folding and tunable charge transfer of an NDI-pentamer","authors":"Dhanyashree Das, Dhrubajyoti Talukdar, Bappaditya Gole","doi":"10.1039/d6qo00055j","DOIUrl":"https://doi.org/10.1039/d6qo00055j","url":null,"abstract":"We present a covalently linked, electroactive, conformationally flexible naphthalene diimide (NDI) pentamer exhibiting unprecedented 10-electron reduction, solvent-dependent folding, and guest-induced tunable charge-transfer (CT). In dichloromethane and chloroform, the oligomer adopts a partially folded state, displaying bright excimer emission at 500 nm. The addition of methyl cyclohexane promotes ordered, long-range folding, thereby enhancing excimer emission. Conversely, the addition of toluene causes folding but quenches the excimer emission while inducing a distinct CT emission. Furthermore, various polyaromatic donors such as anthracene, triphenylene, pyrene, perylene, etc., promote folding by intercalating between NDI layers, forming a long-range alternate donor-acceptor stack with tunable CT absorption. The estimation of the association constant (<em>K<small><sub>a</sub></small></em>) revealed that the strength of CT complexation depends on the donor ability of the guests, with perylene showing the highest association constant. Interestingly, sequential addition of two different donors produces dual CT bands, resulting in broad visible light absorption. This study demonstrates a rare example of guest-dependent tunable CT-driven folding of a flexible multidecker NDI system, offering new insights into the guest-mediated conformational control of foldamer, and an approach towards ordered π-stacked materials.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"334 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bis(polycyclic) aromatic enes (BPAEs), comprising two polyaromatic units bridged by an ethylenic linker, exhibit distinctive electronic properties, yet heteroatom-containing analogues like azafulvalenes remain scarcely explored despite their tunable π-conjugation and redox versatility. Herein, we report an efficient Pd(II)-catalyzed intramolecular diarylation of alkynes that enables the selective synthesis of previously inaccessible azafulvalene-based BPAEs through dual C-H bond activation. This strategy adopts N-aryl and 2-aryl-substituted biarylalkynyl indole scaffolds, enabling modular access to structurally diverse azafulvalene-based BPAEs with precisely incorporated nitrogen atoms. Mechanistic investigations and DFT calculations revealed a pivalate-assisted concerted metallation-deprotonation (CMD) pathway, with the syn-insertion step as the rate-determining process. The addition of trifluoroacetic acid significantly lowers the activation barrier of this key step, enhancing the overall reaction efficiency. The synthesized azafulvalene-based BPAEs exhibit broad and red-shifted absorption bands extending up to 650 nm, low-lying LUMO levels (-3.47 to -3.63 eV), and narrow HOMO-LUMO gaps, consistent with donor-acceptor electronic structures predicted by DFT and TD-DFT calculations. This work establishes a modular and atom-economical synthetic approach for constructing π-extended nitrogen-containing fulvalene frameworks and highlights the potential of azafulvalene-based BPAEs as promising building blocks for advanced organic optoelectronic materials.
{"title":"Pd(II)-Catalyzed intramolecular diarylation of alkynes via dual C-H activation: modular access to azafulvalene-based bis(polycyclic) aromatic enes","authors":"Tienan Jin, Sho Aida, Takuma Sato, Masahiro Terada","doi":"10.1039/d5qo01688f","DOIUrl":"https://doi.org/10.1039/d5qo01688f","url":null,"abstract":"Bis(polycyclic) aromatic enes (BPAEs), comprising two polyaromatic units bridged by an ethylenic linker, exhibit distinctive electronic properties, yet heteroatom-containing analogues like azafulvalenes remain scarcely explored despite their tunable π-conjugation and redox versatility. Herein, we report an efficient Pd(II)-catalyzed intramolecular diarylation of alkynes that enables the selective synthesis of previously inaccessible azafulvalene-based BPAEs through dual C-H bond activation. This strategy adopts N-aryl and 2-aryl-substituted biarylalkynyl indole scaffolds, enabling modular access to structurally diverse azafulvalene-based BPAEs with precisely incorporated nitrogen atoms. Mechanistic investigations and DFT calculations revealed a pivalate-assisted concerted metallation-deprotonation (CMD) pathway, with the syn-insertion step as the rate-determining process. The addition of trifluoroacetic acid significantly lowers the activation barrier of this key step, enhancing the overall reaction efficiency. The synthesized azafulvalene-based BPAEs exhibit broad and red-shifted absorption bands extending up to 650 nm, low-lying LUMO levels (-3.47 to -3.63 eV), and narrow HOMO-LUMO gaps, consistent with donor-acceptor electronic structures predicted by DFT and TD-DFT calculations. This work establishes a modular and atom-economical synthetic approach for constructing π-extended nitrogen-containing fulvalene frameworks and highlights the potential of azafulvalene-based BPAEs as promising building blocks for advanced organic optoelectronic materials.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"41 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, using tricarbazole as the electron donor and four aromatic rings with varied electron cloud density as acceptor, four homologous donor-acceptor (D–A) architectures (TrCzDAa~d) were divergently synthesized and characterized. Their steady-state and transient photophysical properties were subsequently investigated, in which their intramolecular charge transfer transitions were disclosed by solvent-dependent fluorescence spectra. Interestingly, the electron-rich acceptor could result in the blue shift of fluorescence, while the electron-deficient acceptor led to red-shifted fluorescence emission.Furthermore, intense and stable electrochemiluminescence (ECL) signals were observed for all architectures. In contrast, the ECL intensity enhanced with the increasing electron cloud density of the acceptor. Finally, TrCzDAb displaying the optimal ECL performance, was used as the electrode modification material to construct an epinephrine sensor, which demonstrated high sensitivity, excellent stability, and remarkable selectivity. This work elucidated the regulatory role of electron cloud density of the acceptor on the optoelectronic properties of D–A architectures and provides new insights for developing novel high-performance optoelectronic materials and sensors.
{"title":"Tricarbazole-based donor–acceptor architectures with diverse acceptors: synthesis, properties and applications","authors":"Huabi Xie, Yu Zuo, Chengye Yuan, Peng Xu, Ningwen Sun, Hongxing Jia, Jinjin Ding, Qiang Huang, Jinling Zhang","doi":"10.1039/d5qo01633a","DOIUrl":"https://doi.org/10.1039/d5qo01633a","url":null,"abstract":"Herein, using tricarbazole as the electron donor and four aromatic rings with varied electron cloud density as acceptor, four homologous donor-acceptor (D–A) architectures (<strong>TrCzDAa~d</strong>) were divergently synthesized and characterized. Their steady-state and transient photophysical properties were subsequently investigated, in which their intramolecular charge transfer transitions were disclosed by solvent-dependent fluorescence spectra. Interestingly, the electron-rich acceptor could result in the blue shift of fluorescence, while the electron-deficient acceptor led to red-shifted fluorescence emission.Furthermore, intense and stable electrochemiluminescence (ECL) signals were observed for all architectures. In contrast, the ECL intensity enhanced with the increasing electron cloud density of the acceptor. Finally, <strong>TrCzDAb</strong> displaying the optimal ECL performance, was used as the electrode modification material to construct an epinephrine sensor, which demonstrated high sensitivity, excellent stability, and remarkable selectivity. This work elucidated the regulatory role of electron cloud density of the acceptor on the optoelectronic properties of D–A architectures and provides new insights for developing novel high-performance optoelectronic materials and sensors.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"52 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chiral hydroxylamines are important structural motifs and intermediates for a variety of drugs and bioactive molecules. Herein we report the first example of direct asymmetric reductive amination for the direct synthesis of N-H and N-alkyl chiral hydroxylamines. By utilizing complexes generated in situ from a neutral Ir(I) precursor and highly tunable CTPhos ligands as catalysts, we demonstrate that a selection of ketones can be reductively coupled with two types of hydroxylamine nitrogen sources to yield the corresponding chiral products in high yields and enantiomeric excesses, thereby eliminating the need to isolate and use (E)-isomers of oxime intermediates. The series of highly modulated and easily programmable CTPhos ligands promise a suitable enantio-environment for these reactions. Additionally, the chloride atom plays vital roles in the hydrogen addition step by forming a pair of hydrogen bonds among the catalytic species, hydroxylamine, and the protonated oxime intermediate. The H-bonding and other noncovalent interactions stabilize the key transition state and enable high enantioselectivity.
{"title":"Tunable CTPhos and Chloride Enabled Direct Asymmetric Reductive Amination for the Synthesis of Chial Hydroxylamines","authors":"Qishan Liu, Wenji Wang, Biying Liu, Haizhou Huang, Mingxin Chang","doi":"10.1039/d6qo00012f","DOIUrl":"https://doi.org/10.1039/d6qo00012f","url":null,"abstract":"Chiral hydroxylamines are important structural motifs and intermediates for a variety of drugs and bioactive molecules. Herein we report the first example of direct asymmetric reductive amination for the direct synthesis of N-H and N-alkyl chiral hydroxylamines. By utilizing complexes generated in situ from a neutral Ir(I) precursor and highly tunable CTPhos ligands as catalysts, we demonstrate that a selection of ketones can be reductively coupled with two types of hydroxylamine nitrogen sources to yield the corresponding chiral products in high yields and enantiomeric excesses, thereby eliminating the need to isolate and use (E)-isomers of oxime intermediates. The series of highly modulated and easily programmable CTPhos ligands promise a suitable enantio-environment for these reactions. Additionally, the chloride atom plays vital roles in the hydrogen addition step by forming a pair of hydrogen bonds among the catalytic species, hydroxylamine, and the protonated oxime intermediate. The H-bonding and other noncovalent interactions stabilize the key transition state and enable high enantioselectivity.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"207 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shoucai Wang, Ziren Chen, Fei Xue, Yonghong Zhang, Bin Wang, Shaofeng Wu, Yu Xia, Weiwei Jin, Fanghua Ji, Chenjiang Liu
Direct C-H silylation of (thio)chromones was achieved by the combination of hydrogen atom transfer (HAT), photoredox and transition metal catalysis under ambient air conditions. High regioselectivity, oxidant-and noble metal-free conditions, and synergistic multiple catalysis were the major features of this protocol. Moreover, this approach can be safely conducted on a gram scale with hydrogen as the only byproduct.6
在环境空气条件下，通过氢原子转移（HAT）、光氧化还原（photoredox）和过渡金属催化（transition metal catalytic）的结合，实现了（thio）铬的直接C-H硅基化。高区域选择性、无氧化和无贵金属条件、协同多重催化是该工艺的主要特点。而且，这种方法可以安全地以克为单位进行，氢气是唯一的副产品
{"title":"Visible Light-Induced Regioselective/Dehydrogenative Silylation of (Thio)chromones via Tricatalytic Process","authors":"Shoucai Wang, Ziren Chen, Fei Xue, Yonghong Zhang, Bin Wang, Shaofeng Wu, Yu Xia, Weiwei Jin, Fanghua Ji, Chenjiang Liu","doi":"10.1039/d6qo00081a","DOIUrl":"https://doi.org/10.1039/d6qo00081a","url":null,"abstract":"Direct C-H silylation of (thio)chromones was achieved by the combination of hydrogen atom transfer (HAT), photoredox and transition metal catalysis under ambient air conditions. High regioselectivity, oxidant-and noble metal-free conditions, and synergistic multiple catalysis were the major features of this protocol. Moreover, this approach can be safely conducted on a gram scale with hydrogen as the only byproduct.6","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"157 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Albert Artigas, Nicolas Vanthuyne, Jean-Valère Naubron, Denis Hagebaum-Reignier, Yannick Carissan, Maxime Remond, Ludovic Favereau, Harald Bock, Fabien Durola, Yoann Coquerel
The in-depth analysis of the configurational, (chir)optical and aromatic properties of two diastereomeric singly and triply twisted Möbius-shaped macrocycles, the cyclotris[5]helicenes, in which three [5]helicene fragments with like and unlike helicity are connected by three C(sp2)–C(sp2) single bonds, led to the conclusion that global π electronic delocalization exists in these molecules. This was analyzed as a consequence of the reduced torsion angle (≤ 30°) at the C(sp2)–C(sp2) single bonds connecting the [5]helicene fragments. The enantiomers of both diastereomeric cyclotris[5]helicenes were thoroughly analyzed experimentally by unpolarized and circularly polarized vibrational, absorption and luminescence (fluorescence and phosphorescence) precision spectroscopies, all correlated with advanced DFT models, which provided insightful data on their S0, S1 and T1 electronic states, and on their chirality. The theoretical analyses of aromaticity in both diastereomeric cyclotris[5]helicene macrocycles, as compared with recently reported analogues, confirmed their Möbius aromaticity.
{"title":"Electronic Properties of Diastereomeric Möbius Shaped Cyclotris[5]helicenes","authors":"Albert Artigas, Nicolas Vanthuyne, Jean-Valère Naubron, Denis Hagebaum-Reignier, Yannick Carissan, Maxime Remond, Ludovic Favereau, Harald Bock, Fabien Durola, Yoann Coquerel","doi":"10.1039/d5qo01741f","DOIUrl":"https://doi.org/10.1039/d5qo01741f","url":null,"abstract":"The in-depth analysis of the configurational, (chir)optical and aromatic properties of two diastereomeric singly and triply twisted Möbius-shaped macrocycles, the cyclotris[5]helicenes, in which three [5]helicene fragments with like and unlike helicity are connected by three C(sp<small><sup>2</sup></small>)–C(sp<small><sup>2</sup></small>) single bonds, led to the conclusion that global π electronic delocalization exists in these molecules. This was analyzed as a consequence of the reduced torsion angle (≤ 30°) at the C(sp<small><sup>2</sup></small>)–C(sp<small><sup>2</sup></small>) single bonds connecting the [5]helicene fragments. The enantiomers of both diastereomeric cyclotris[5]helicenes were thoroughly analyzed experimentally by unpolarized and circularly polarized vibrational, absorption and luminescence (fluorescence and phosphorescence) precision spectroscopies, all correlated with advanced DFT models, which provided insightful data on their S<small><sub>0</sub></small>, S<small><sub>1</sub></small> and T<small><sub>1</sub></small> electronic states, and on their chirality. The theoretical analyses of aromaticity in both diastereomeric cyclotris[5]helicene macrocycles, as compared with recently reported analogues, confirmed their Möbius aromaticity.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"150 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhan-Wei Fu, Chen-Yu Dou, Xiong Zhou, Feifei Fang, Mu-Peng Luo, Shu-Rong Ban, Shi Cao, Shou-Guo Wang
Axially chiral scaffolds are privileged motifs in natural products, bioactive agents, and asymmetric catalysis. Here, we present an enantioselective C–H arylation of 2-pyridones at the C6 position with diazo compounds, catalyzed by a chiral Rh(III) complex. This strategy enables direct, efficient, and modular construction of C–C axially chiral 2-pyridones with high yields and outstanding enantioselectivity (up to 99% yield, 99% ee). The method features a broad substrate scope, operational simplicity, and scalability, offering a versatile and practical route to diverse useful atropisomeric architectures.
{"title":"Rh(III)-Catalyzed Enantioselective C–H Arylation: Atroposelective Synthesis of 2-Pyridones from Diazo Compounds","authors":"Zhan-Wei Fu, Chen-Yu Dou, Xiong Zhou, Feifei Fang, Mu-Peng Luo, Shu-Rong Ban, Shi Cao, Shou-Guo Wang","doi":"10.1039/d5qo01764e","DOIUrl":"https://doi.org/10.1039/d5qo01764e","url":null,"abstract":"Axially chiral scaffolds are privileged motifs in natural products, bioactive agents, and asymmetric catalysis. Here, we present an enantioselective C–H arylation of 2-pyridones at the C6 position with diazo compounds, catalyzed by a chiral Rh(III) complex. This strategy enables direct, efficient, and modular construction of C–C axially chiral 2-pyridones with high yields and outstanding enantioselectivity (up to 99% yield, 99% ee). The method features a broad substrate scope, operational simplicity, and scalability, offering a versatile and practical route to diverse useful atropisomeric architectures.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"24 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yue Wu, Kuirong Fu, Song Qin, Ming Ouyang, Zhiyao Yang, Yimin Cai, Wen Feng, Lihua Yuan, Xiaowei Li
Photoresponsive host macrocycles are attractive for their wide scope of applications in controlled molecular recognition, information storage, switchable catalysis, and smart materials. One of the challenges along this line lies in the construction of large size hosts with multiple photoactive groups, e.g. azobenzene, for light-controlled guest capture and release. Herein, we report a giant hydrogen-bonded aramide macrocycle incorporating four azobenzene units that enables light-controlled binding and release of cucurbit[5]uril (CB[5]). Single-crystal X-ray diffraction reveals that the tetra-azo-macrocycle adopts a relatively rigid figure of eight conformation constrained by intramolecular hydrogen bonding within the macrocyclic framework backbone. Photochemical studies demonstrate efficient photoisomerization from the thermally stable E,E,E,E-isomer to other isomeric states, reaching a maximum conversion of 95.7%. The amide oxygen-decorated cavity of the macrocycle selectively accommodates the smaller host CB[5] through multi-point hydrogen-bonding interactions, giving rise to forming a host-in-host complex. Most notably, light irradiation triggers the release of CB[5] in the presence of sodium cation, in sharp contrast to previously reported host-in-host systems in which guest release is typically difficult and relies solely on subtle host shape changes. This work demonstrates a rare example of exploiting a H-bonded aramide macrocycle with multiple azobenzene units for manoeuvring the uptake and release process in response to external photo-stimulus, and also implicates new possibilities for designing multi-state light-responsive materials.
{"title":"A photoswitchable tetra-azo macrocycle enabling light-controlled host-in-host binding and release of cucurbit[5]uril","authors":"Yue Wu, Kuirong Fu, Song Qin, Ming Ouyang, Zhiyao Yang, Yimin Cai, Wen Feng, Lihua Yuan, Xiaowei Li","doi":"10.1039/d5qo01751c","DOIUrl":"https://doi.org/10.1039/d5qo01751c","url":null,"abstract":"Photoresponsive host macrocycles are attractive for their wide scope of applications in controlled molecular recognition, information storage, switchable catalysis, and smart materials. One of the challenges along this line lies in the construction of large size hosts with multiple photoactive groups, e.g. azobenzene, for light-controlled guest capture and release. Herein, we report a giant hydrogen-bonded aramide macrocycle incorporating four azobenzene units that enables light-controlled binding and release of cucurbit[5]uril (CB[5]). Single-crystal X-ray diffraction reveals that the tetra-azo-macrocycle adopts a relatively rigid figure of eight conformation constrained by intramolecular hydrogen bonding within the macrocyclic framework backbone. Photochemical studies demonstrate efficient photoisomerization from the thermally stable <em>E</em>,<em>E</em>,<em>E</em>,<em>E</em>-isomer to other isomeric states, reaching a maximum conversion of 95.7%. The amide oxygen-decorated cavity of the macrocycle selectively accommodates the smaller host CB[5] through multi-point hydrogen-bonding interactions, giving rise to forming a <em>host-in-host</em> complex. Most notably, light irradiation triggers the release of CB[5] in the presence of sodium cation, in sharp contrast to previously reported <em>host-in-host</em> systems in which guest release is typically difficult and relies solely on subtle host shape changes. This work demonstrates a rare example of exploiting a H-bonded aramide macrocycle with multiple azobenzene units for manoeuvring the uptake and release process in response to external photo-stimulus, and also implicates new possibilities for designing multi-state light-responsive materials.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"295 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yufan Yang, Dongxu Wang, Dongyang Jiang, Kaixuan Pan, Yingchen Wang, Luai Ji, Wanshu Wang, Lu Gao, Fu Peng, Zhenlei Song
A visible light-induced radical coupling of β-amino iodides and enones has been developed. This transformation offers efficient access to 1,5-amino ketones (25 examples, 71-96% yield), which serve as versatile precursors for the construction of cis-2,6-disubstituted piperidines. By integrating continuous-flow chemistry, the process becomes amenable to scale-up, affording higher yields and shorter reaction times compared to conventional batch reactions in flasks. The synthetic utility of this methodology was demonstrated through concise and symmetric total syntheses of cis-2,6-piperidine alkaloids, including H3 receptor agonists and (-)-6-epi-porantheridine.
{"title":"Flow Chemistry-Assisted Visible Light-Induced Radical Addition of β-Amino Iodides with Enones en Route to Efficient Construction of cis-2,6-Piperidines","authors":"Yufan Yang, Dongxu Wang, Dongyang Jiang, Kaixuan Pan, Yingchen Wang, Luai Ji, Wanshu Wang, Lu Gao, Fu Peng, Zhenlei Song","doi":"10.1039/d5qo01747e","DOIUrl":"https://doi.org/10.1039/d5qo01747e","url":null,"abstract":"A visible light-induced radical coupling of β-amino iodides and enones has been developed. This transformation offers efficient access to 1,5-amino ketones (25 examples, 71-96% yield), which serve as versatile precursors for the construction of cis-2,6-disubstituted piperidines. By integrating continuous-flow chemistry, the process becomes amenable to scale-up, affording higher yields and shorter reaction times compared to conventional batch reactions in flasks. The synthetic utility of this methodology was demonstrated through concise and symmetric total syntheses of cis-2,6-piperidine alkaloids, including H3 receptor agonists and (-)-6-epi-porantheridine.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"2 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：