Pub Date : 2025-03-03DOI: 10.1021/acscatal.5c00165
Runze Zhang, Keting Zhou, Yu Xia, Sanzhong Luo
The oxidation of thiols to form disulfide bonds is a crucial reaction in biological systems. Inspired by methanol dehydrogenase (MDH), we developed a bioinspired quinone-catalyzed aerobic oxidation reaction for thiol oxidation to disulfides. Based on mechanistic studies, we have confirmed that a semiquinone radical anion, coordinated by a lanthanum ion, serves as the critical intermediate. The thiol-quinone redox shuttle was further shown to mediate the MDH-like activity in the aerobic oxidation of alcohols.
{"title":"Bioinspired Lanthanide-ortho-Quinone-Catalyzed Aerobic Disulfide Formation","authors":"Runze Zhang, Keting Zhou, Yu Xia, Sanzhong Luo","doi":"10.1021/acscatal.5c00165","DOIUrl":"https://doi.org/10.1021/acscatal.5c00165","url":null,"abstract":"The oxidation of thiols to form disulfide bonds is a crucial reaction in biological systems. Inspired by methanol dehydrogenase (MDH), we developed a bioinspired quinone-catalyzed aerobic oxidation reaction for thiol oxidation to disulfides. Based on mechanistic studies, we have confirmed that a semiquinone radical anion, coordinated by a lanthanum ion, serves as the critical intermediate. The thiol-quinone redox shuttle was further shown to mediate the MDH-like activity in the aerobic oxidation of alcohols.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"34 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538344","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: 10.1021/acscatal.4c06929
Anastasios Orestis Grammenos, Rémi F. André, Fernando Igoa Saldaña, Mahima Kamra, Markus Antonietti, Mateusz Odziomek
Electrochemically driven organic reactions present an appealing alternative to traditional catalytic methods, which often involve harsh conditions. To date, commercial (noble) metal electrodes have dominated the field, with the development of effective, cheap, and stable electrode materials being overlooked. Nitrogen-doped carbons (NDCs) are widely used in electrocatalysis, energy storage, and even electrochemical hydrogen storage, which can be potentially beneficial in hydrogenation reactions, yet their potential in organic electrosynthesis has remained underexplored. In this study, we synthesized a nanoporous NDC from 7,7,8,8-tetracyanoquinodimethane via the salt-melt method and employed it for the electrochemical hydrogenation of maleic acid to succinic acid (SA). The NDC demonstrated high SA yield rates with nearly 100% Faradaic efficiency, with its performance being comparable or better than conventional (photo)catalytic methods, while using milder conditions, with water as the hydrogen source, and without any metal catalysts. Owing to the NDC’s chemical structure, which causes specific adsorptive interactions, the reaction mechanism resembles that of noble metals, where protons reduced in the Volmer step recombine with coadsorbed maleic acid in a subsequent chemical step. Additionally, due to these adsorptive interactions, the reaction could be directed at will toward the nonredox electrochemical isomerization to fumaric acid, by simply adjusting the potential and electrolyte acidity.
{"title":"Harnessing the Electrochemical Hydrogen Storage Capability of N-Doped Carbons for Metal-Free Hydrogenations","authors":"Anastasios Orestis Grammenos, Rémi F. André, Fernando Igoa Saldaña, Mahima Kamra, Markus Antonietti, Mateusz Odziomek","doi":"10.1021/acscatal.4c06929","DOIUrl":"https://doi.org/10.1021/acscatal.4c06929","url":null,"abstract":"Electrochemically driven organic reactions present an appealing alternative to traditional catalytic methods, which often involve harsh conditions. To date, commercial (noble) metal electrodes have dominated the field, with the development of effective, cheap, and stable electrode materials being overlooked. Nitrogen-doped carbons (NDCs) are widely used in electrocatalysis, energy storage, and even electrochemical hydrogen storage, which can be potentially beneficial in hydrogenation reactions, yet their potential in organic electrosynthesis has remained underexplored. In this study, we synthesized a nanoporous NDC from 7,7,8,8-tetracyanoquinodimethane via the salt-melt method and employed it for the electrochemical hydrogenation of maleic acid to succinic acid (SA). The NDC demonstrated high SA yield rates with nearly 100% Faradaic efficiency, with its performance being comparable or better than conventional (photo)catalytic methods, while using milder conditions, with water as the hydrogen source, and without any metal catalysts. Owing to the NDC’s chemical structure, which causes specific adsorptive interactions, the reaction mechanism resembles that of noble metals, where protons reduced in the Volmer step recombine with coadsorbed maleic acid in a subsequent chemical step. Additionally, due to these adsorptive interactions, the reaction could be directed at will toward the nonredox electrochemical isomerization to fumaric acid, by simply adjusting the potential and electrolyte acidity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"52 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538340","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 : 2025-03-02DOI: 10.1021/acscatal.4c06338
Julia G. Buschermöhle, Julia Müller-Hülstede, Henrike Schmies, Dana Schonvogel, Tanja Zierdt, Rene Lucka, Franz Renz, Peter Wagner, Michael Wark
High-temperature proton exchange membrane fuel cells (HT-PEMFCs) typically rely on platinum-based catalysts, which require high loadings due to Pt deactivation by phosphates from the phosphoric acid-doped membrane. As alternative catalysts for the oxygen reduction reaction, metal–nitrogen-carbons (M–N–Cs) are promising due to their high intrinsic activity and tolerance to phosphates. However, low volumetric activity compared to Pt nanoparticles on carbon blacks (Pt/C) and insufficient stability limit their applicability. In order to enhance the stability and activity of Fe–N–Cs, this study investigates the incorporation of tin as a second metal, resulting in Fe–Sn–N–Cs, prepared by a metal–organic framework (MOF)-based approach. Stable and highly active catalysts with total mass activities of 8.2 A g–1 (Fe–Sn–N–C (1:1)) and 19.3 A g–1 (Fe–Sn–N–C (1:0.3)) in 0.5 mol L–1 H3PO4, drastically exceeding those of the commercial Fe–N–C catalyst PMF-014401 (Pajarito-Powder, 4.8 A g–1), are obtained by a synthesis without the need for subsequent purification steps. A stress test under harsh conditions (0.6–1.0 VRHE, 10,000 cycles, O2-saturated electrolyte) ascertains stability-enhancing effects of tin, highlighting an increase in stability in conjunction with the tin content. These results provide a valuable contribution to the development of cost-effective HT-PEMFCs by significantly enhancing the catalytic activity of platinum group metal-free catalysts.
{"title":"Fe–Sn–N–C Catalysts: Advancing Oxygen Reduction Reaction Performance","authors":"Julia G. Buschermöhle, Julia Müller-Hülstede, Henrike Schmies, Dana Schonvogel, Tanja Zierdt, Rene Lucka, Franz Renz, Peter Wagner, Michael Wark","doi":"10.1021/acscatal.4c06338","DOIUrl":"https://doi.org/10.1021/acscatal.4c06338","url":null,"abstract":"High-temperature proton exchange membrane fuel cells (HT-PEMFCs) typically rely on platinum-based catalysts, which require high loadings due to Pt deactivation by phosphates from the phosphoric acid-doped membrane. As alternative catalysts for the oxygen reduction reaction, metal–nitrogen-carbons (M–N–Cs) are promising due to their high intrinsic activity and tolerance to phosphates. However, low volumetric activity compared to Pt nanoparticles on carbon blacks (Pt/C) and insufficient stability limit their applicability. In order to enhance the stability and activity of Fe–N–Cs, this study investigates the incorporation of tin as a second metal, resulting in Fe–Sn–N–Cs, prepared by a metal–organic framework (MOF)-based approach. Stable and highly active catalysts with total mass activities of 8.2 A g<sup>–1</sup> (Fe–Sn–N–C (1:1)) and 19.3 A g<sup>–1</sup> (Fe–Sn–N–C (1:0.3)) in 0.5 mol L<sup>–1</sup> H<sub>3</sub>PO<sub>4</sub>, drastically exceeding those of the commercial Fe–N–C catalyst PMF-014401 (Pajarito-Powder, 4.8 A g<sup>–1</sup>), are obtained by a synthesis without the need for subsequent purification steps. A stress test under harsh conditions (0.6–1.0 V<sub>RHE</sub>, 10,000 cycles, O<sub>2</sub>-saturated electrolyte) ascertains stability-enhancing effects of tin, highlighting an increase in stability in conjunction with the tin content. These results provide a valuable contribution to the development of cost-effective HT-PEMFCs by significantly enhancing the catalytic activity of platinum group metal-free catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"34 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528260","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 : 2025-03-02DOI: 10.1021/acscatal.4c07251
Giulia Tarantino, Timothy G. Burrow, Matteo Aramini, Michael L. Baker, Ceri Hammond
The catalytic conversion of C–H to C–F bonds is a critical synthetic transformation of relevance to the pharmaceutical, agrochemical, and medicinal chemical industries. When coupled with an oxidant and a fluorine donor, biomimetic Mn-porphyrins have been shown to be capable of achieving this reaction. However, the definition of the active forms of these fluorinating Mn-porphyrins remains an unsolved challenge, which limits mechanistic understanding of the process and makes it challenging to systematically design better catalytic materials. Herein, we present a combination of kinetic, spectroscopic, and theoretical studies focused on alkane fluorination over Mn-containing porphyrins. Specifically, by correlating kinetic studies with resonance Raman, UV–vis, and high-energy resolution fluorescence detected X-ray absorption spectroscopic analysis of the various states of the catalyst, we provide evidence that a 6-coordinated Mn(IV) complex with −F and −OI(F)Ar axial ligands is the active species responsible for selective fluorination via Hydrogen Atom Transfer. This active state is distinct from the Mn═O species previously proposed to be the active intermediates for alkane fluorination and oxidation.
{"title":"Elucidation of the Active Mn-Species Responsible for Alkane Fluorination Catalyzed by Mn Porphyrins","authors":"Giulia Tarantino, Timothy G. Burrow, Matteo Aramini, Michael L. Baker, Ceri Hammond","doi":"10.1021/acscatal.4c07251","DOIUrl":"https://doi.org/10.1021/acscatal.4c07251","url":null,"abstract":"The catalytic conversion of C–H to C–F bonds is a critical synthetic transformation of relevance to the pharmaceutical, agrochemical, and medicinal chemical industries. When coupled with an oxidant and a fluorine donor, biomimetic Mn-porphyrins have been shown to be capable of achieving this reaction. However, the definition of the active forms of these fluorinating Mn-porphyrins remains an unsolved challenge, which limits mechanistic understanding of the process and makes it challenging to systematically design better catalytic materials. Herein, we present a combination of kinetic, spectroscopic, and theoretical studies focused on alkane fluorination over Mn-containing porphyrins. Specifically, by correlating kinetic studies with resonance Raman, UV–vis, and high-energy resolution fluorescence detected X-ray absorption spectroscopic analysis of the various states of the catalyst, we provide evidence that a 6-coordinated Mn(IV) complex with −F and −OI(F)Ar axial ligands is the active species responsible for selective fluorination via Hydrogen Atom Transfer. This active state is distinct from the Mn═O species previously proposed to be the active intermediates for alkane fluorination and oxidation.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"66 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532428","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 : 2025-03-02DOI: 10.1021/acscatal.4c06394
Michael T. Tang, Joakim Halldin Stenlid, Jinyu Guo, Elizabeth Corson, William Tarpeh, Frank Abild-Pedersen
The electrochemical reduction of nitrate (NO3R) to ammonia is a bold yet conceivable way of producing ammonia using renewable electricity. However, serious challenges remain in finding optimal electrocatalysts for the process. An atomistic understanding of the surface energetics behind the NO3R is needed in order to design an efficient catalyst. Herein, we combine energetics from density functional theory and microkinetic modeling to demonstrate how surface descriptors can help simplify the search for efficient NO3R electrocatalysts. We illustrate the strong correlations between transition-state energetics and O* binding energies for adsorbed nitrate and nitrite on transition metals. For intermediates from NO* and beyond, we compare the benefits of using either the N* or H* binding energies to predict reduction onset potentials. These insights enable us to develop a simple microkinetic model that elucidates the surface coverages of intermediates and the product selectivity of NO3R across a range of potentials and transition metals. We show that the model adequately corroborates with quasi-steady-state rates observed experimentally.
{"title":"Nitrate Reduction Modeling under Acidic Conditions with Late Transition Metals","authors":"Michael T. Tang, Joakim Halldin Stenlid, Jinyu Guo, Elizabeth Corson, William Tarpeh, Frank Abild-Pedersen","doi":"10.1021/acscatal.4c06394","DOIUrl":"https://doi.org/10.1021/acscatal.4c06394","url":null,"abstract":"The electrochemical reduction of nitrate (NO<sub>3</sub>R) to ammonia is a bold yet conceivable way of producing ammonia using renewable electricity. However, serious challenges remain in finding optimal electrocatalysts for the process. An atomistic understanding of the surface energetics behind the NO<sub>3</sub>R is needed in order to design an efficient catalyst. Herein, we combine energetics from density functional theory and microkinetic modeling to demonstrate how surface descriptors can help simplify the search for efficient NO<sub>3</sub>R electrocatalysts. We illustrate the strong correlations between transition-state energetics and O* binding energies for adsorbed nitrate and nitrite on transition metals. For intermediates from NO* and beyond, we compare the benefits of using either the N* or H* binding energies to predict reduction onset potentials. These insights enable us to develop a simple microkinetic model that elucidates the surface coverages of intermediates and the product selectivity of NO<sub>3</sub>R across a range of potentials and transition metals. We show that the model adequately corroborates with quasi-steady-state rates observed experimentally.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"39 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532399","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 : 2025-03-01DOI: 10.1021/acscatal.4c04934
Shuya Li, Udani K. Wijethunga, Chun Chu, Saerona Kim, Weiwei Zheng, Benjamin D. Sherman, Chang Geun Yoo, Seunghyun Lee, Gyu Leem
Ruthenium(II) polypyridine complexes have been widely studied for applications in dye-sensitized solar cells and artificial photosynthesis. Here, this work reports studies of intermolecular charge transfer from metal-to-ligand charge transfer (MLCT) excitation of Ru(II)-based chromophores onto TiO2 nanoparticles to a hydrogen atom transfer (HAT) mediator and photocatalytic activation of HAT for cleavage of the C–C bond in the aryl ether linkages at room temperature. Initial studies demonstrated intermolecular energy/electron transfer among the photoexcited photocatalyst, bis(2,2′-bipyridine)(4,4′-dicarboxy-2,2′-bipyridine)Ru(II) (RuC) coated TiO2 nanoparticles (RuC/TiO2 NPs), the N-hydroxy-phthalimide (NHPI) HAT mediator, and the diol substrate 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (LMC-ol). Photophysical studies of RuC/TiO2 NPs in the presence of NHPI/2,6-lutidine and LMC-ol exhibited a highly effective quenching for photoexcited RuC*/TiO2 with KSV = 7.21 × 103 M–1 compared to the lower quenching constant (KSV ∼ 0.11 × 103 M–1) observed for RuC*/TiO2 with only LMC-ol in acetonitrile solution. Under ambient temperature and aerobic conditions, the oxidative cleavage products of 3,4-dimethoxybenzaldehyde and 2-(2-methoxyphenoxy)-acetaldehyde from LMC-ol were obtained with the oxidized ketone product. This result indicates that the solar driven HAT-mediated process allows catalysis of the oxidative cleavage of C–C bonds in the aryl ether linkages via a one-pot cleavage reaction at room temperature. This photocatalytic system presents a possible approach to support lignin depolymerization targeting value-added aromatic chemicals and developing polymer degradation.
{"title":"Photoinduced Hydrogen Atom Transfer Catalysis with Ruthenium Polypyridyl Coated-TiO2 Nanoparticles for Selective C–C Bond Cleavage in a Lignin Model Compound","authors":"Shuya Li, Udani K. Wijethunga, Chun Chu, Saerona Kim, Weiwei Zheng, Benjamin D. Sherman, Chang Geun Yoo, Seunghyun Lee, Gyu Leem","doi":"10.1021/acscatal.4c04934","DOIUrl":"https://doi.org/10.1021/acscatal.4c04934","url":null,"abstract":"Ruthenium(II) polypyridine complexes have been widely studied for applications in dye-sensitized solar cells and artificial photosynthesis. Here, this work reports studies of intermolecular charge transfer from metal-to-ligand charge transfer (MLCT) excitation of Ru(II)-based chromophores onto TiO<sub>2</sub> nanoparticles to a hydrogen atom transfer (HAT) mediator and photocatalytic activation of HAT for cleavage of the C–C bond in the aryl ether linkages at room temperature. Initial studies demonstrated intermolecular energy/electron transfer among the photoexcited photocatalyst, bis(2,2′-bipyridine)(4,4′-dicarboxy-2,2′-bipyridine)Ru(II) (<b>RuC</b>) coated TiO<sub>2</sub> nanoparticles (RuC/TiO<sub>2</sub> NPs), the <i>N</i>-hydroxy-phthalimide (NHPI) HAT mediator, and the diol substrate 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (<b>LMC-ol</b>). Photophysical studies of RuC/TiO<sub>2</sub> NPs in the presence of NHPI/2,6-lutidine and <b>LMC-ol</b> exhibited a highly effective quenching for photoexcited RuC*/TiO<sub>2</sub> with K<sub>SV</sub> = 7.21 × 10<sup>3</sup> M<sup>–1</sup> compared to the lower quenching constant (K<sub>SV</sub> ∼ 0.11 × 10<sup>3</sup> M<sup>–1</sup>) observed for RuC*/TiO<sub>2</sub> with only <b>LMC-ol</b> in acetonitrile solution. Under ambient temperature and aerobic conditions, the oxidative cleavage products of 3,4-dimethoxybenzaldehyde and 2-(2-methoxyphenoxy)-acetaldehyde from <b>LMC-ol</b> were obtained with the oxidized ketone product. This result indicates that the solar driven HAT-mediated process allows catalysis of the oxidative cleavage of C–C bonds in the aryl ether linkages via a one-pot cleavage reaction at room temperature. This photocatalytic system presents a possible approach to support lignin depolymerization targeting value-added aromatic chemicals and developing polymer degradation.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"8 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526512","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}
Electrochemical synthesis of ethylamine from acetonitrile with H2O is a promising alternative to the traditional H2-based process but is challenged by the sluggish hydrogenation process with the inefficient supply of active hydrogen species (H*). Herein, we report an accelerated hydrogen transfer strategy to facilitate on-site electrochemical hydrogenation of acetonitrile for ethylamine synthesis. This strategy was realized by a monolithic electrode composed of oxygen vacancies (OVs)-rich titanium dioxide nanoarrays grown on Ti foam in combination with Ni single atoms (Ni1/OVs-TiO2 NA), which enabled the efficient electrochemical water dissociation into H* along with the optimized electronic structure of surface lattice oxygens by leveraging adjacent OVs, effectively weakening the binding strength of O–H bonds for the subsequent fast transfer of confined H* mediated by surface lattice oxygens. With further incorporation of Ni single atoms as H* trapping centers for the hydrogenation step, the as-prepared Ni1/OVs-TiO2 NA delivered an impressive electrocatalytic performance of acetonitrile hydrogenation with an ethylamine yield rate of 6.93 mmol h–1 mgNi–1 and a Faraday efficiency of 94%, 8.8-fold higher than that of OVs-free counterpart (0.78 mmol h–1 mgNi–1, 39%). This work clarifies the promotion effect of surface lattice oxygen on hydrogen-transfer-related electrochemical hydrogenation reactions and offers a water-based ethylamine synthesis strategy.
{"title":"Surface Lattice Oxygen Confined Hydrogen Transfer for Electrochemical Acetonitrile Hydrogenation","authors":"Hao Zhang, Linghao Yu, Yancai Yao, Biao Zhou, Jundi Cheng, Xupeng Liu, Ziyue Chen, Hao Zhang, Long Zhao, Lizhi Zhang","doi":"10.1021/acscatal.4c07928","DOIUrl":"https://doi.org/10.1021/acscatal.4c07928","url":null,"abstract":"Electrochemical synthesis of ethylamine from acetonitrile with H<sub>2</sub>O is a promising alternative to the traditional H<sub>2</sub>-based process but is challenged by the sluggish hydrogenation process with the inefficient supply of active hydrogen species (H*). Herein, we report an accelerated hydrogen transfer strategy to facilitate on-site electrochemical hydrogenation of acetonitrile for ethylamine synthesis. This strategy was realized by a monolithic electrode composed of oxygen vacancies (OVs)-rich titanium dioxide nanoarrays grown on Ti foam in combination with Ni single atoms (Ni<sub>1</sub>/OVs-TiO<sub>2</sub> NA), which enabled the efficient electrochemical water dissociation into H* along with the optimized electronic structure of surface lattice oxygens by leveraging adjacent OVs, effectively weakening the binding strength of O–H bonds for the subsequent fast transfer of confined H* mediated by surface lattice oxygens. With further incorporation of Ni single atoms as H* trapping centers for the hydrogenation step, the as-prepared Ni<sub>1</sub>/OVs-TiO<sub>2</sub> NA delivered an impressive electrocatalytic performance of acetonitrile hydrogenation with an ethylamine yield rate of 6.93 mmol h<sup>–1</sup> mg<sub>Ni</sub><sup>–1</sup> and a Faraday efficiency of 94%, 8.8-fold higher than that of OVs-free counterpart (0.78 mmol h<sup>–1</sup> mg<sub>Ni</sub><sup>–1</sup>, 39%). This work clarifies the promotion effect of surface lattice oxygen on hydrogen-transfer-related electrochemical hydrogenation reactions and offers a water-based ethylamine synthesis strategy.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"52 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526513","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: 10.1021/acscatal.4c06782
Yi Zhou, Yi Jin, Xinxuan Li, Xi-Jia Liu, Yi Wang, Zhi-Xiang Yu
Transition-metal-catalyzed cycloadditions to access nine-membered carbocycles are challenging, with only three documented examples so far. Here, we report the design of an eight-carbon synthon, vinyl biscyclopropanes (VBCPs), which undergoes Rh-catalyzed [8 + 1] cycloaddition with CO to furnish nine-membered carbocycles. This strategy enables the synthesis of 5/9 bicyclic compounds from VBCPs with diverse substituents. Mechanistic studies via quantum chemistry calculations revealed concerted C–C bond cleavages in the two cyclopropyl moieties of cis-VBCP substrates, whereas a stepwise pathway is adopted by trans-VBCPs. The key intermediate in the [8 + 1] cycloaddition is a nine-membered rhodacycle, which undergoes CO insertion followed by reductive elimination to deliver the desired nine-membered carbocycle. However, a competing β-H elimination pathway diverts the reaction, yielding a triene side product. For less effective or unsuccessful substrates, the sluggish CO insertion in the [8 + 1] cycloaddition pathway is attributed to the transannular interaction and unfavorable entropic effect during the formation of a challenging 10-membered rhodacycle in the CO insertion transition state, posing a similar obstacle for designing cycloadditions with ring sizes larger than nine.
{"title":"Rh-Catalyzed [8+1] Cycloaddition of Vinyl Biscyclopropanes with CO for the Synthesis of Nine-Membered Carbocycles","authors":"Yi Zhou, Yi Jin, Xinxuan Li, Xi-Jia Liu, Yi Wang, Zhi-Xiang Yu","doi":"10.1021/acscatal.4c06782","DOIUrl":"https://doi.org/10.1021/acscatal.4c06782","url":null,"abstract":"Transition-metal-catalyzed cycloadditions to access nine-membered carbocycles are challenging, with only three documented examples so far. Here, we report the design of an eight-carbon synthon, vinyl biscyclopropanes (VBCPs), which undergoes Rh-catalyzed [8 + 1] cycloaddition with CO to furnish nine-membered carbocycles. This strategy enables the synthesis of 5/9 bicyclic compounds from VBCPs with diverse substituents. Mechanistic studies via quantum chemistry calculations revealed concerted C–C bond cleavages in the two cyclopropyl moieties of <i>cis</i>-VBCP substrates, whereas a stepwise pathway is adopted by <i>trans</i>-VBCPs. The key intermediate in the [8 + 1] cycloaddition is a nine-membered rhodacycle, which undergoes CO insertion followed by reductive elimination to deliver the desired nine-membered carbocycle. However, a competing β-H elimination pathway diverts the reaction, yielding a triene side product. For less effective or unsuccessful substrates, the sluggish CO insertion in the [8 + 1] cycloaddition pathway is attributed to the transannular interaction and unfavorable entropic effect during the formation of a challenging 10-membered rhodacycle in the CO insertion transition state, posing a similar obstacle for designing cycloadditions with ring sizes larger than nine.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"31 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518293","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: 10.1021/acscatal.5c00006
Xianyang Long, Dong Zhu, Shifa Zhu
Vinylsilanes have significant value in organic synthesis, materials design, and organometallic chemistry. Compared to traditional methods for the synthesis of vinyl- or multivinylsilanes using dangerous multichlorosilanes and stoichiometric vinyl Grignard reagents, the earth-abundant transition-metal-catalyzed hydrosilylation of acetylene with multihydrosilane represents a more straightforward and atom-economical approach. However, selective and controllable acetylene hydrosilylation using multihydrosilanes is still challenging. Herein, we report a cobalt-catalyzed selective and controllable acetylene hydrosilylation with various hydrosilanes (including primary, secondary, and tertiary silanes). Mono-, bis-, trivinylsilane, or bis(silane)s are produced by a simple adjustment of the conditions. Both the reactivity and selectivity can be fine-tuned by changing the ligands, which allows for the highly selective and divergent synthesis of vinylsilanes. Detailed mechanistic studies indicate that the primary or secondary silane-assisted reduction of CoII to produce an active low-valence CoI intermediate is a prerequisite for the catalytic reaction. The CoII reduction is also required for the reaction of the bulky and less reactive tertiary silanes. The obtained vinylsilanes and bis(silane)s have potential as silicon-containing monomers for the synthesis of organosilicon polymers.
{"title":"Cobalt-Catalyzed Chemoselective and Divergent Synthesis of Vinylsilanes through Hydrosilylation of Acetylene","authors":"Xianyang Long, Dong Zhu, Shifa Zhu","doi":"10.1021/acscatal.5c00006","DOIUrl":"https://doi.org/10.1021/acscatal.5c00006","url":null,"abstract":"Vinylsilanes have significant value in organic synthesis, materials design, and organometallic chemistry. Compared to traditional methods for the synthesis of vinyl- or multivinylsilanes using dangerous multichlorosilanes and stoichiometric vinyl Grignard reagents, the earth-abundant transition-metal-catalyzed hydrosilylation of acetylene with multihydrosilane represents a more straightforward and atom-economical approach. However, selective and controllable acetylene hydrosilylation using multihydrosilanes is still challenging. Herein, we report a cobalt-catalyzed selective and controllable acetylene hydrosilylation with various hydrosilanes (including primary, secondary, and tertiary silanes). Mono-, bis-, trivinylsilane, or bis(silane)s are produced by a simple adjustment of the conditions. Both the reactivity and selectivity can be fine-tuned by changing the ligands, which allows for the highly selective and divergent synthesis of vinylsilanes. Detailed mechanistic studies indicate that the primary or secondary silane-assisted reduction of Co<sup>II</sup> to produce an active low-valence Co<sup>I</sup> intermediate is a prerequisite for the catalytic reaction. The Co<sup>II</sup> reduction is also required for the reaction of the bulky and less reactive tertiary silanes. The obtained vinylsilanes and bis(silane)s have potential as silicon-containing monomers for the synthesis of organosilicon polymers.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"28 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518296","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: 10.1021/acscatal.5c00250
Suman Dana, Neeraj Kumar Pandit, Philipp Boos, Tristan von Münchow, Sven Erik Peters, Sven Trienes, Laura Haberstock, Regine Herbst-Irmer, Dietmar Stalke, Lutz Ackermann
Enantioselective electrocatalyzed C–H activations have emerged as a transformative platform for the assembly of value-added chiral organic molecules. Despite the recent progress, the construction of multiple C(sp3)-stereogenic centers via a C(sp3)–C(sp3) bond formation has thus far proven to be elusive. In contrast, we herein report an annulative C–H activation strategy, generating chiral Fsp3-rich molecules with high levels of diastereo- and enantioselectivity. κ2-N,O-oxazoline preligands were effectively employed in enantioselective cobalt(III)-catalyzed C–H activation reactions. Using DFT-derived descriptors and regression statistical modeling, we performed a parametrization study on the modularity of chiral κ2-N,O-oxazoline preligands. The study resulted in a model describing ligands’ selectivity characterized by key steric, electronic, and interaction behaviors.
{"title":"Parametrization of κ2-N,O-Oxazoline Preligands for Enantioselective Cobaltaelectro-Catalyzed C–H Activations","authors":"Suman Dana, Neeraj Kumar Pandit, Philipp Boos, Tristan von Münchow, Sven Erik Peters, Sven Trienes, Laura Haberstock, Regine Herbst-Irmer, Dietmar Stalke, Lutz Ackermann","doi":"10.1021/acscatal.5c00250","DOIUrl":"https://doi.org/10.1021/acscatal.5c00250","url":null,"abstract":"Enantioselective electrocatalyzed C–H activations have emerged as a transformative platform for the assembly of value-added chiral organic molecules. Despite the recent progress, the construction of multiple C(sp<sup>3</sup>)-stereogenic centers via a C(sp<sup>3</sup>)–C(sp<sup>3</sup>) bond formation has thus far proven to be elusive. In contrast, we herein report an annulative C–H activation strategy, generating chiral Fsp<sup>3</sup>-rich molecules with high levels of diastereo- and enantioselectivity. κ<sup>2</sup>-<i>N</i>,<i>O</i>-oxazoline preligands were effectively employed in enantioselective cobalt(III)-catalyzed C–H activation reactions. Using DFT-derived descriptors and regression statistical modeling, we performed a parametrization study on the modularity of chiral κ<sup>2</sup>-<i>N</i>,<i>O</i>-oxazoline preligands. The study resulted in a model describing ligands’ selectivity characterized by key steric, electronic, and interaction behaviors.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"34 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526514","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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