Pub Date : 2025-03-05DOI: 10.1016/j.chempr.2024.102391
Qiong Liu, Hui Cheng, Ching Kit Tommy Wun, Tianxiang Chen, Tsz Woon Benedict Lo, Fuxian Wang
Photocatalytic reduction of CO2 in flue gas faces significant challenges due to the low CO2 concentration and the presence of oxygen (O2), which induces competitive oxygen reduction reactions, as well as the sluggish kinetics and complex product separation of oxidation half-reactions. Herein, we developed a dual copper (Cu)/platinum (Pt) atom on carbon nitride (CN-CuPt) photocatalyst, achieving synergistic ethylene production through low CO2 concentration (i.e., 12% CO2) reduction coupled with isopropanol oxidation to acetone for the first example. A benchmark photocatalytic ethylene yield of 778.6 μmolh−1gcat−1 with a high selectivity of 87.0% is obtained, outperforming all the state-of-the-art CO2 photocatalysts. What’s more, the CN-CuPt exhibits high oxygen tolerance, and more than 90% of its performance is retained under the interference of 5% oxygen due to oxygen inhibition by Cu species. Our strategy of regulating adsorption sites shows great potential for designing catalysts for practical photocatalytic reduction of flue gas.
{"title":"Oxygen-tolerant photocatalytic conversion of simulated flue gas to ethylene","authors":"Qiong Liu, Hui Cheng, Ching Kit Tommy Wun, Tianxiang Chen, Tsz Woon Benedict Lo, Fuxian Wang","doi":"10.1016/j.chempr.2024.102391","DOIUrl":"https://doi.org/10.1016/j.chempr.2024.102391","url":null,"abstract":"Photocatalytic reduction of CO<sub>2</sub> in flue gas faces significant challenges due to the low CO<sub>2</sub> concentration and the presence of oxygen (O<sub>2</sub>), which induces competitive oxygen reduction reactions, as well as the sluggish kinetics and complex product separation of oxidation half-reactions. Herein, we developed a dual copper (Cu)/platinum (Pt) atom on carbon nitride (CN-CuPt) photocatalyst, achieving synergistic ethylene production through low CO<sub>2</sub> concentration (i.e., 12% CO<sub>2</sub>) reduction coupled with isopropanol oxidation to acetone for the first example. A benchmark photocatalytic ethylene yield of 778.6 μmolh<sup>−1</sup>g<sub>cat</sub><sup>−1</sup> with a high selectivity of 87.0% is obtained, outperforming all the state-of-the-art CO<sub>2</sub> photocatalysts. What’s more, the CN-CuPt exhibits high oxygen tolerance, and more than 90% of its performance is retained under the interference of 5% oxygen due to oxygen inhibition by Cu species. Our strategy of regulating adsorption sites shows great potential for designing catalysts for practical photocatalytic reduction of flue gas.","PeriodicalId":268,"journal":{"name":"Chem","volume":"67 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561047","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}
Pub Date : 2025-03-05DOI: 10.1016/j.chempr.2025.102460
Amrita Singh-Morgan, Kim Trösch, Anna Weinfurter, Michael Inniger, Yuan-Zi Xu, Victor Mougel
The electrochemical synthesis of ammonia presents a promising pathway to decarbonize and electrify the production of the world’s second-largest commodity chemical. Among potential reactants, NOx gases stand out owing to their favorable thermodynamics, advantageous kinetics, and availability from both combustion emissions and nitrogen-fixation processes, such as plasma-induced atmospheric nitrogen oxidation. However, the typically low concentration of NOx in these sources poses significant challenges for electrochemical performance, particularly due to limitations in reactant mass transport. In this work, we report on the use of a porous nickel catalyst in a membrane electrode assembly (MEA) electrolyzer to enable the direct use of a dilute nitric oxide (NO) feed. The rational optimization of reactant mass transport led to the attainment of maximum values of NO-to-NH3 single-pass conversion of 93%, faradaic efficiency for ammonia of 92%, and ammonium production rate of 556 μmol/h⋅cm2.
{"title":"Efficient electrochemical conversion of nitric oxide to ammonia using a porous nickel catalyst in a membrane electrode assembly electrolyzer","authors":"Amrita Singh-Morgan, Kim Trösch, Anna Weinfurter, Michael Inniger, Yuan-Zi Xu, Victor Mougel","doi":"10.1016/j.chempr.2025.102460","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102460","url":null,"abstract":"The electrochemical synthesis of ammonia presents a promising pathway to decarbonize and electrify the production of the world’s second-largest commodity chemical. Among potential reactants, NO<sub>x</sub> gases stand out owing to their favorable thermodynamics, advantageous kinetics, and availability from both combustion emissions and nitrogen-fixation processes, such as plasma-induced atmospheric nitrogen oxidation. However, the typically low concentration of NO<sub>x</sub> in these sources poses significant challenges for electrochemical performance, particularly due to limitations in reactant mass transport. In this work, we report on the use of a porous nickel catalyst in a membrane electrode assembly (MEA) electrolyzer to enable the direct use of a dilute nitric oxide (NO) feed. The rational optimization of reactant mass transport led to the attainment of maximum values of NO-to-NH<sub>3</sub> single-pass conversion of 93%, faradaic efficiency for ammonia of 92%, and ammonium production rate of 556 μmol/h⋅cm<sup>2</sup>.","PeriodicalId":268,"journal":{"name":"Chem","volume":"67 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546620","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}
Ammonia (NH3) is considered a biomarker of liver and kidney diseases; sensitive and visible fluorescence sensors are expected to achieve quantitative detection of breath NH3, although low accuracy makes them difficult to apply in breath tests. Herein, we adopted a “double-response-reverse fluorescence” strategy via in situ encapsulation of a metal nanocluster (MNC) into a hydrogen-bonded organic framework, successfully constructing an ultra-accurate ratiometric fluorescence sensor (Pt2Cu4@HOF-101). With a combination of π-conjugated HOF and luminescent MNC, two kinds of NH3 recognition sites were preciously assembled and raised significant orbital energy changes, thus realizing a strong response to trace NH3. The precision-assembled Pt2Cu4@HOF-101 has been eloquently inspected by three-dimensional electron diffraction, which comprehensively uncovered the structure-induced double-response-reverse sensing mechanism. Notably, Pt2Cu4@HOF-101 enabled exact quantification of the NH3 exhaled, and the measured expiratory concentration was highly positively correlated with the blood test, which offers a new approach for the painless diagnosis of liver and kidney diseases.
{"title":"Encapsulation of metal nanoclusters into hydrogen-bonded organic frameworks for double-response-reverse ammonia fluorescence sensing","authors":"Yuxin Wang, Jia Yao, Shitao Wu, Chao Zhi, Lifei Yin, Zhengxuan Song, Jing Wang, Lixia Ling, Yanhang Ma, Daliang Zhang, Jinping Li, Libo Li, Banglin Chen","doi":"10.1016/j.chempr.2025.102457","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102457","url":null,"abstract":"Ammonia (NH<sub>3</sub>) is considered a biomarker of liver and kidney diseases; sensitive and visible fluorescence sensors are expected to achieve quantitative detection of breath NH<sub>3</sub>, although low accuracy makes them difficult to apply in breath tests. Herein, we adopted a “double-response-reverse fluorescence” strategy via <em>in situ</em> encapsulation of a metal nanocluster (MNC) into a hydrogen-bonded organic framework, successfully constructing an ultra-accurate ratiometric fluorescence sensor (Pt<sub>2</sub>Cu<sub>4</sub>@HOF-101). With a combination of π-conjugated HOF and luminescent MNC, two kinds of NH<sub>3</sub> recognition sites were preciously assembled and raised significant orbital energy changes, thus realizing a strong response to trace NH<sub>3</sub>. The precision-assembled Pt<sub>2</sub>Cu<sub>4</sub>@HOF-101 has been eloquently inspected by three-dimensional electron diffraction, which comprehensively uncovered the structure-induced double-response-reverse sensing mechanism. Notably, Pt<sub>2</sub>Cu<sub>4</sub>@HOF-101 enabled exact quantification of the NH<sub>3</sub> exhaled, and the measured expiratory concentration was highly positively correlated with the blood test, which offers a new approach for the painless diagnosis of liver and kidney diseases.","PeriodicalId":268,"journal":{"name":"Chem","volume":"35 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539184","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}
Pub Date : 2025-03-03DOI: 10.1016/j.chempr.2025.102441
Minghang Jiang, Xi Chen, Fasheng Chen, Mengjun Wang, Xiaojun Luo, Yi He, Caijun Wu, Liyun Zhang, Xiao Li, Xuemei Liao, Zhenju Jiang, Zhong Jin
Ammonia (NH3) synthesis using N2 as reaction raw material powered by renewable electricity provides a promising route to realize artificial N2 fixation. However, the activation of N2 molecules, a crucial step in the process, remains challenging. Recently, significant progress has been made in developing effective strategies, including lithium (Li)/calcium (Ca)-mediated and plasma-assisted technologies, to enhance N2 activation. These technologies involve the conversion of inert N2 into more reactive nitrogen-containing species, which are further converted to produce NH3. In this review, we present recent pioneering works on effective N2 activation strategies, including Li/Ca-mediated and plasma-assisted technologies for electrochemical NH3 synthesis. Finally, we highlight the remaining challenges and prospects. We hope that this review will provide profound insights and inspire innovative thinking in the area of effective N2 activation strategies, thereby significantly advancing the field of electrochemical NH3 synthesis.
{"title":"Effective N2 activation strategies for electrochemical ammonia synthesis","authors":"Minghang Jiang, Xi Chen, Fasheng Chen, Mengjun Wang, Xiaojun Luo, Yi He, Caijun Wu, Liyun Zhang, Xiao Li, Xuemei Liao, Zhenju Jiang, Zhong Jin","doi":"10.1016/j.chempr.2025.102441","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102441","url":null,"abstract":"Ammonia (NH<sub>3</sub>) synthesis using N<sub>2</sub> as reaction raw material powered by renewable electricity provides a promising route to realize artificial N<sub>2</sub> fixation. However, the activation of N<sub>2</sub> molecules, a crucial step in the process, remains challenging. Recently, significant progress has been made in developing effective strategies, including lithium (Li)/calcium (Ca)-mediated and plasma-assisted technologies, to enhance N<sub>2</sub> activation. These technologies involve the conversion of inert N<sub>2</sub> into more reactive nitrogen-containing species, which are further converted to produce NH<sub>3</sub>. In this review, we present recent pioneering works on effective N<sub>2</sub> activation strategies, including Li/Ca-mediated and plasma-assisted technologies for electrochemical NH<sub>3</sub> synthesis. Finally, we highlight the remaining challenges and prospects. We hope that this review will provide profound insights and inspire innovative thinking in the area of effective N<sub>2</sub> activation strategies, thereby significantly advancing the field of electrochemical NH<sub>3</sub> synthesis.","PeriodicalId":268,"journal":{"name":"Chem","volume":"53 4 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532402","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}
Pub Date : 2025-02-28DOI: 10.1016/j.chempr.2025.102450
Rohan Bhimpuria, Monika Tomar, Anders Thapper, Mårten Ahlquist, K. Eszter Borbas
CO2 conversion to value-added chemicals is a crucial technology toward carbon-neutral fuels. Photocatalysis using sunlight is an energy-efficient alternative to electrochemical and thermal CO2 reduction. Photocatalysts usually yield either CO or formate with varying degrees of selectivity. Herein, a lanthanide-based photocatalytic platform producing CO with the highest turnover to date is reported. The catalyst consists of a pendant amine for CO2 capture and a light-harvesting sensitizer that generates the reactive divalent lanthanide center. CO2 reduction to CO was possible with high selectivity and reactivity by virtue of a distinct mechanistic pathway involving Sm(II), carbamate, and CO2⋅− as identified intermediates. Attractive (bi)carbonate CO2 feedstocks were efficiently converted to CO. Depending on the conditions, the selective synthesis of formate, methane, and methanol was also possible, demonstrating the wide utility of the platform.
{"title":"Photocatalytic product-selective reduction of CO2, CO, and carbonates","authors":"Rohan Bhimpuria, Monika Tomar, Anders Thapper, Mårten Ahlquist, K. Eszter Borbas","doi":"10.1016/j.chempr.2025.102450","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102450","url":null,"abstract":"CO<sub>2</sub> conversion to value-added chemicals is a crucial technology toward carbon-neutral fuels. Photocatalysis using sunlight is an energy-efficient alternative to electrochemical and thermal CO<sub>2</sub> reduction. Photocatalysts usually yield either CO or formate with varying degrees of selectivity. Herein, a lanthanide-based photocatalytic platform producing CO with the highest turnover to date is reported. The catalyst consists of a pendant amine for CO<sub>2</sub> capture and a light-harvesting sensitizer that generates the reactive divalent lanthanide center. CO<sub>2</sub> reduction to CO was possible with high selectivity and reactivity by virtue of a distinct mechanistic pathway involving Sm(II), carbamate, and CO<sub>2</sub><sup>⋅−</sup> as identified intermediates. Attractive (bi)carbonate CO<sub>2</sub> feedstocks were efficiently converted to CO. Depending on the conditions, the selective synthesis of formate, methane, and methanol was also possible, demonstrating the wide utility of the platform.","PeriodicalId":268,"journal":{"name":"Chem","volume":"32 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518452","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}
Pub Date : 2025-02-27DOI: 10.1016/j.chempr.2025.102491
Yosta de Stigter, Maarten Merkx
Advances in artificial intelligence are revolutionizing protein design, and new methods are emerging rapidly. In this issue of Chem, Yeh and co-workers leverage recent deep-learning-based tools to create a series of improved de novo luciferases and color variants that successfully address the limitations of native luciferases.
{"title":"Next-generation de novo luciferases: How artificial intelligence is improving its own designs at light speed","authors":"Yosta de Stigter, Maarten Merkx","doi":"10.1016/j.chempr.2025.102491","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102491","url":null,"abstract":"Advances in artificial intelligence are revolutionizing protein design, and new methods are emerging rapidly. In this issue of <em>Chem</em>, Yeh and co-workers leverage recent deep-learning-based tools to create a series of improved <em>de novo</em> luciferases and color variants that successfully address the limitations of native luciferases.","PeriodicalId":268,"journal":{"name":"Chem","volume":"28 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143507488","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}
Pub Date : 2025-02-26DOI: 10.1016/j.chempr.2025.102444
Xin-Feng Wang, Rui Wei, Qiuming Liang, Chaopeng Hu, Liu Leo Liu
The synthesis, characterization, and reactivity of keteniminyl anions [R1C=C=NR2]− (R1 = diazaphospholidinyl or diazathiophospholidinyl, R2 = 2,6-dimethylphenyl), a hitherto uncharted functional group, are the primary focus of this study. The keteniminyl anions are characterized by their nucleophilic/basic anionic carbon and π electrons, which are extensively delocalized along the PCCN chain. These anions undergo a range of facile reactions, such as protonation, alkylation, silylation, and metalation at the carbon site, leading to various ketenimine derivatives. They also participate in hydroamination reactions, yielding amino enamide functional groups. Additionally, the diazaphospholidinyl substituent in keteniminyl anions acts as a previously underappreciated weak π-electron acceptor when the phosphorus atom is in a pyramidalized state, thereby facilitating the stabilization of the electron-rich anionic carbon. The isolation of such keteniminyl anions not only represents a significant synthetic achievement but also heralds the potential for the future isolation of electron-rich species featuring diazaphospholidinyl substituents.
{"title":"Stable crystalline keteniminyl anions","authors":"Xin-Feng Wang, Rui Wei, Qiuming Liang, Chaopeng Hu, Liu Leo Liu","doi":"10.1016/j.chempr.2025.102444","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102444","url":null,"abstract":"The synthesis, characterization, and reactivity of keteniminyl anions [R<sup>1</sup>C=C=NR<sup>2</sup>]<sup>−</sup> (R<sup>1</sup> = diazaphospholidinyl or diazathiophospholidinyl, R<sup>2</sup> = 2,6-dimethylphenyl), a hitherto uncharted functional group, are the primary focus of this study. The keteniminyl anions are characterized by their nucleophilic/basic anionic carbon and π electrons, which are extensively delocalized along the PCCN chain. These anions undergo a range of facile reactions, such as protonation, alkylation, silylation, and metalation at the carbon site, leading to various ketenimine derivatives. They also participate in hydroamination reactions, yielding amino enamide functional groups. Additionally, the diazaphospholidinyl substituent in keteniminyl anions acts as a previously underappreciated weak π-electron acceptor when the phosphorus atom is in a pyramidalized state, thereby facilitating the stabilization of the electron-rich anionic carbon. The isolation of such keteniminyl anions not only represents a significant synthetic achievement but also heralds the potential for the future isolation of electron-rich species featuring diazaphospholidinyl substituents.","PeriodicalId":268,"journal":{"name":"Chem","volume":"6 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496055","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}
Pub Date : 2025-02-25DOI: 10.1016/j.chempr.2025.102442
Yiheng Lu, Melina Knezevic, Alessandro Prescimone, Bernd Goldfuss, Konrad Tiefenbacher
Although the field of C(sp3)–H oxidation has progressed tremendously over the last decades, the selective oxidation of non-activated positions on hydrocarbon skeletons is still highly challenging. It usually requires the presence of a suitable functional handle in proximity to the desired oxidation site. Here, we present a novel approach to catalyst-directed C–H oxidation that relies on substrate binding via the solvophobic effect in fluorinated alcohols and thus is independent of specific functional groups on the substrate. The supramolecular catalyst Mn(mcp)-RS2 enables the preferential oxidation at the fifth position from the less-hindered side on aliphatic substrates.
{"title":"Site-selective C(sp3)–H oxidation of alkyl substrates devoid of functional handles","authors":"Yiheng Lu, Melina Knezevic, Alessandro Prescimone, Bernd Goldfuss, Konrad Tiefenbacher","doi":"10.1016/j.chempr.2025.102442","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102442","url":null,"abstract":"Although the field of C(sp<sup>3</sup>)–H oxidation has progressed tremendously over the last decades, the selective oxidation of non-activated positions on hydrocarbon skeletons is still highly challenging. It usually requires the presence of a suitable functional handle in proximity to the desired oxidation site. Here, we present a novel approach to catalyst-directed C–H oxidation that relies on substrate binding via the solvophobic effect in fluorinated alcohols and thus is independent of specific functional groups on the substrate. The supramolecular catalyst Mn(mcp)-RS<sub>2</sub> enables the preferential oxidation at the fifth position from the less-hindered side on aliphatic substrates.","PeriodicalId":268,"journal":{"name":"Chem","volume":"47 11 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143486401","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}
Pub Date : 2025-02-25DOI: 10.1016/j.chempr.2025.102440
Dong-Xing Tan, Jie Zhou, Cheng-Yu Gu, Ze-Yu Li, Yun-Jie Shen, Fu-She Han
Although the total synthesis of aspidosperma natural products has been extensively investigated, the members possessing diverse functionalities at C3 and/or C5, which display much stronger bioactivity than the non-functionalized congeners, have not been accomplished due to the structural challenges. Herein, the first catalytic asymmetric total syntheses of C11-demethoxymelotenine, 3-oxotabersonine, voacafrine I, and 3α/3β-acetonyltabersonine are presented. Our synthesis hinged on the development of an organocatalyzed desymmetric enantioselective Michael/aldol reaction of 2-(2-nitrophenyl)cyclohexane-1,3-dione for the efficient construction of a chiral [3.3.1]-bridged bicyclic scaffold and a ring opening-reorganizing tactic of the bridged bicycle for elegant construction of a 6-5-6-5-6 pentacyclic ring system bearing functionalities amenable to distinguishable elaborations at C3, C5, and C19 positions. Utilizing the strategic polycyclic core, the enantioselective total syntheses of six previously unconquered aspidosperma-type alkaloids and stereoisomers have been achieved via a divergent manner through appropriately manipulating the functional groups at C3, C5, and C19 at the late stage.
{"title":"Enantioselective total syntheses of melotenine-, voacafrine-, and tabersonine-type Aspidosperma indole alkaloids","authors":"Dong-Xing Tan, Jie Zhou, Cheng-Yu Gu, Ze-Yu Li, Yun-Jie Shen, Fu-She Han","doi":"10.1016/j.chempr.2025.102440","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102440","url":null,"abstract":"Although the total synthesis of <em>aspidosperma</em> natural products has been extensively investigated, the members possessing diverse functionalities at C3 and/or C5, which display much stronger bioactivity than the non-functionalized congeners, have not been accomplished due to the structural challenges. Herein, the first catalytic asymmetric total syntheses of C11-demethoxymelotenine, 3-oxotabersonine, voacafrine I, and 3α/3β-acetonyltabersonine are presented. Our synthesis hinged on the development of an organocatalyzed desymmetric enantioselective Michael/aldol reaction of 2-(2-nitrophenyl)cyclohexane-1,3-dione for the efficient construction of a chiral [3.3.1]-bridged bicyclic scaffold and a ring opening-reorganizing tactic of the bridged bicycle for elegant construction of a 6-5-6-5-6 pentacyclic ring system bearing functionalities amenable to distinguishable elaborations at C3, C5, and C19 positions. Utilizing the strategic polycyclic core, the enantioselective total syntheses of six previously unconquered <em>aspidosperma</em>-type alkaloids and stereoisomers have been achieved via a divergent manner through appropriately manipulating the functional groups at C3, C5, and C19 at the late stage.","PeriodicalId":268,"journal":{"name":"Chem","volume":"23 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143486428","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}
Pub Date : 2025-02-24DOI: 10.1016/j.chempr.2025.102439
Jingxian Huang, Hui Yang, Xiao Chen, Rong Liang, Fuk-Yee Kwong, Zhifeng Huang, Ming Wah Wong, Ying-Yeung Yeung
Asymmetric catalytic halofunctionalization has gained prominence for introducing carbon point chirality and halogen functionality simultaneously. Axially chiral biaryls possess a range of promising applications; however, their synthesis through asymmetric halogenation is limited. Here, we report the synthesis of C–N axially chiral N-arylcarbazoles through desymmetrizing atroposelective bromination. This process is facilitated by a catalyst blend consisting of a chiral phosphoric acid and an achiral Lewis base. The resulting bromo-carbazoles contain readily modifiable halogen handles, allowing for the introduction of additional chiral axes through diastereoselective cross-coupling. These axially chiral compounds exhibit high fluorescence quantum yields and satisfactory circularly polarized luminescence performance. Mechanistic studies indicate that the chiral phosphate and achiral pyridine catalysts cross-assemble through C–H nonclassical hydrogen bonds and C–X halogen bonds, creating a confined microenvironment for efficient enantiofacial discrimination of substrates. This research paves the way for an approach to synthesizing mimics of planar chiral arenes for applications in materials science.
{"title":"Desymmetrizing atroposelective bromination of N-arylcarbazoles enabled by cross-assembled bifunctional catalysts","authors":"Jingxian Huang, Hui Yang, Xiao Chen, Rong Liang, Fuk-Yee Kwong, Zhifeng Huang, Ming Wah Wong, Ying-Yeung Yeung","doi":"10.1016/j.chempr.2025.102439","DOIUrl":"https://doi.org/10.1016/j.chempr.2025.102439","url":null,"abstract":"Asymmetric catalytic halofunctionalization has gained prominence for introducing carbon point chirality and halogen functionality simultaneously. Axially chiral biaryls possess a range of promising applications; however, their synthesis through asymmetric halogenation is limited. Here, we report the synthesis of C–N axially chiral <em>N</em>-arylcarbazoles through desymmetrizing atroposelective bromination. This process is facilitated by a catalyst blend consisting of a chiral phosphoric acid and an achiral Lewis base. The resulting bromo-carbazoles contain readily modifiable halogen handles, allowing for the introduction of additional chiral axes through diastereoselective cross-coupling. These axially chiral compounds exhibit high fluorescence quantum yields and satisfactory circularly polarized luminescence performance. Mechanistic studies indicate that the chiral phosphate and achiral pyridine catalysts cross-assemble through C–H nonclassical hydrogen bonds and C–X halogen bonds, creating a confined microenvironment for efficient enantiofacial discrimination of substrates. This research paves the way for an approach to synthesizing mimics of planar chiral arenes for applications in materials science.","PeriodicalId":268,"journal":{"name":"Chem","volume":"2 1","pages":""},"PeriodicalIF":23.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477530","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}
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