Pub Date : 2024-10-15DOI: 10.1016/j.checat.2024.101134
Sophie H. van Vreeswijk, Luke A. Parker, Arnaud T. Sanderse, Ramon Oord, Florian Meirer, Bert M. Weckhuysen
The methanol-to-hydrocarbons (MTH) catalyst deactivation is reversible, and deactivating coke molecules can be removed via regeneration experiments. Regeneration of small-pore zeolite SSZ-13 first leads to the elimination of polyaromatic deactivating compounds, leaving the active aromatic intermediates intact. Partial regeneration experiments can provide an alternative approach to study small-pore zeolites by mimicking co-feeding of aromatic intermediates. Catalyst properties and reaction intermediates were followed with operando UV-visible spectroscopy and X-ray diffraction. It was shown that all the coke is formed within the zeolite cages and that the lattice expansion is due to the formation of hydrocarbon molecules. Additionally, indications for separate reaction mechanisms to produce ethylene and propylene were established. With confocal fluorescence microscopy (CFM), it was determined that upon regeneration, the hydrocarbons were less conjugated and more homogeneously distributed. A full hydrocarbon pool mechanism was established for the MTH reaction over zeolite SSZ-13.
{"title":"Utilizing operando catalyst regeneration to uncover insights in the methanol-to-hydrocarbons process","authors":"Sophie H. van Vreeswijk, Luke A. Parker, Arnaud T. Sanderse, Ramon Oord, Florian Meirer, Bert M. Weckhuysen","doi":"10.1016/j.checat.2024.101134","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101134","url":null,"abstract":"The methanol-to-hydrocarbons (MTH) catalyst deactivation is reversible, and deactivating coke molecules can be removed via regeneration experiments. Regeneration of small-pore zeolite SSZ-13 first leads to the elimination of polyaromatic deactivating compounds, leaving the active aromatic intermediates intact. Partial regeneration experiments can provide an alternative approach to study small-pore zeolites by mimicking co-feeding of aromatic intermediates. Catalyst properties and reaction intermediates were followed with <em>operando</em> UV-visible spectroscopy and X-ray diffraction. It was shown that all the coke is formed within the zeolite cages and that the lattice expansion is due to the formation of hydrocarbon molecules. Additionally, indications for separate reaction mechanisms to produce ethylene and propylene were established. With confocal fluorescence microscopy (CFM), it was determined that upon regeneration, the hydrocarbons were less conjugated and more homogeneously distributed. A full hydrocarbon pool mechanism was established for the MTH reaction over zeolite SSZ-13.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"23 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.checat.2024.101146
Pascal Hauk, Sven Trienes, Fabrice Gallou, Lutz Ackermann, Joanna Wencel-Delord
Micellar reaction conditions have emerged as a powerful and sustainable strategy in synthetic organic chemistry. Numerous transformations have been reported to work under micellar conditions; however, transformations such as C−H activation remain scarce, and the compartmentalization effects are not yet fully understood. Herein, we describe a rational surfactant design for challenging C−H activation. Incorporating a pyridone ligand into a commercially available PS-750-M surfactant allows for overcoming the compartmentalization issues, resulting in an efficient Ru-catalyzed direct arylation under mild reaction conditions and with excellent selectivity. Physicochemical characterization of this surfactant shed light on the inherent properties of the novel PyOH-750-M surfactant while recycling of the surfactant allows for product formation with a low E-factor of 5.5 without a drop in reactivity.
{"title":"Next-generation functional surfactant for mild C−H arylation under micellar conditions","authors":"Pascal Hauk, Sven Trienes, Fabrice Gallou, Lutz Ackermann, Joanna Wencel-Delord","doi":"10.1016/j.checat.2024.101146","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101146","url":null,"abstract":"Micellar reaction conditions have emerged as a powerful and sustainable strategy in synthetic organic chemistry. Numerous transformations have been reported to work under micellar conditions; however, transformations such as C−H activation remain scarce, and the compartmentalization effects are not yet fully understood. Herein, we describe a rational surfactant design for challenging C−H activation. Incorporating a pyridone ligand into a commercially available PS-750-M surfactant allows for overcoming the compartmentalization issues, resulting in an efficient Ru-catalyzed direct arylation under mild reaction conditions and with excellent selectivity. Physicochemical characterization of this surfactant shed light on the inherent properties of the novel PyOH-750-M surfactant while recycling of the surfactant allows for product formation with a low E-factor of 5.5 without a drop in reactivity.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"108 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.checat.2024.101145
Ziyu Fang, Chao Ye, Tao Ling, Huiping Ji, Chenbao Lu, Changchun Ke, Xiaodong Zhuang, Jieqiong Shan
In the face of the imminent challenges of climate change, hydrogen holds the potential to replace fossil fuels as a green and sustainable energy resource. Anion-exchange membrane water electrolyzer (AEMWE) is a quickly rising technology for hydrogen production due to various advantages, including an inexpensive membrane, non-precious metal catalysts, compact size, easy integration with and adaptation to green power, etc. AEMWE involves a typical combination of electrocatalysts, an anion-exchange membrane, membrane electrode assembly, flow channel design, system integration, and green power fluctuation working condition adaptability. However, AEMWE suffers from unsatisfactory operational durability from both individual components and system integration levels, restricting its large-scale application. The development of highly durable AEMWE requires rational and systematic analysis and evaluation of each component for practical integration. This review discusses the durability-limiting factors and common strategies to improve stability based on each level of the AEMWE system, thus fostering future academic and industrial development of highly durable AEMWEs.
{"title":"Stability challenges of anion-exchange membrane water electrolyzers from components to integration level","authors":"Ziyu Fang, Chao Ye, Tao Ling, Huiping Ji, Chenbao Lu, Changchun Ke, Xiaodong Zhuang, Jieqiong Shan","doi":"10.1016/j.checat.2024.101145","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101145","url":null,"abstract":"In the face of the imminent challenges of climate change, hydrogen holds the potential to replace fossil fuels as a green and sustainable energy resource. Anion-exchange membrane water electrolyzer (AEMWE) is a quickly rising technology for hydrogen production due to various advantages, including an inexpensive membrane, non-precious metal catalysts, compact size, easy integration with and adaptation to green power, etc. AEMWE involves a typical combination of electrocatalysts, an anion-exchange membrane, membrane electrode assembly, flow channel design, system integration, and green power fluctuation working condition adaptability. However, AEMWE suffers from unsatisfactory operational durability from both individual components and system integration levels, restricting its large-scale application. The development of highly durable AEMWE requires rational and systematic analysis and evaluation of each component for practical integration. This review discusses the durability-limiting factors and common strategies to improve stability based on each level of the AEMWE system, thus fostering future academic and industrial development of highly durable AEMWEs.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"2 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.checat.2024.101130
Christian Schroeder, Maricruz Sanchez-Sanchez
Transition metal ions (TMIs) hosted in zeolites have potential for generating highly active and selective catalysts. The speciation of metal ions inside the microporous zeolite pore system, including geometric constraints and anchoring points, grouping, and nuclearity of species, is not well understood. Determination of the location and structure of active sites is challenging because different species co-exist in the same zeolite, and complexity is added by their dynamics under reaction conditions. Three parameters are influential on the speciation of active TMIs in zeolites: (1) zeolite properties, including framework structure, composition, and metal loadings; (2) mobility of TMI species inside the zeolite micropores; and (3) influence of other inorganic species present in the reaction spaces. In our view, molecular-level understanding of metal-ion-exchanged zeolite catalysts requires a set of characterization and computational techniques that should go hand in hand with refined synthetic methods selectively generating active species.
{"title":"Unlocking the potential for pseudo-molecular catalysts via understanding the activity of transition metal ionic species in zeolites","authors":"Christian Schroeder, Maricruz Sanchez-Sanchez","doi":"10.1016/j.checat.2024.101130","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101130","url":null,"abstract":"Transition metal ions (TMIs) hosted in zeolites have potential for generating highly active and selective catalysts. The speciation of metal ions inside the microporous zeolite pore system, including geometric constraints and anchoring points, grouping, and nuclearity of species, is not well understood. Determination of the location and structure of active sites is challenging because different species co-exist in the same zeolite, and complexity is added by their dynamics under reaction conditions. Three parameters are influential on the speciation of active TMIs in zeolites: (1) zeolite properties, including framework structure, composition, and metal loadings; (2) mobility of TMI species inside the zeolite micropores; and (3) influence of other inorganic species present in the reaction spaces. In our view, molecular-level understanding of metal-ion-exchanged zeolite catalysts requires a set of characterization and computational techniques that should go hand in hand with refined synthetic methods selectively generating active species.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"21 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the challenges in designing efficient electrocatalysts is rationalizing the impact of crystal and electronic structures on catalytic activity. Here, we synthesized four BaRuO3 polymorphs with different structures and investigated the d-d interaction stemming from face-sharing RuO6. The polymorph 9R-BaRuO3 has the highest percentage of face-sharing RuO6 octahedra and, therefore, the strongest d-d interaction; it shows the best activity and stability in catalyzing alkaline hydrogen evolution reactions (HER). Specifically, 9R-BaRuO3 displays a small Tafel slope of 30 mV dec−1 and a low overpotential of η10 < 51 mV. This performance is attributed to its high intrinsic activity delivered by the d-d interaction and is intimately related to the crystal structure. The micron-sized 9R-BaRuO3 powders are stable under industrial plasma spraying and carry a current density of 0.4 A/cm2 @ 1.74 V in commercial alkaline water electrolyzers. The results on catalytic activities and crystal structure provide insight for designing better electrocatalysts for practical applications.
{"title":"Ruthenate perovskite with face-sharing motifs for alkaline hydrogen evolution","authors":"Chuanhui Zhu, Hao Tian, Pengfei Tan, Bin Huang, Shuang Zhao, Guohong Cai, Chongyang Yuan, Mei-Huan Zhao, Meng Cao, Jianfa Zhao, Luchuan Shi, Fang Qi, Haili Song, Keke Huang, Shouhua Feng, Mark Croft, Changqing Jin, Shuk-Yin Tong, Man-Rong Li","doi":"10.1016/j.checat.2024.101132","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101132","url":null,"abstract":"One of the challenges in designing efficient electrocatalysts is rationalizing the impact of crystal and electronic structures on catalytic activity. Here, we synthesized four BaRuO<sub>3</sub> polymorphs with different structures and investigated the <em>d-d</em> interaction stemming from face-sharing RuO<sub>6</sub>. The polymorph 9<em>R</em>-BaRuO<sub>3</sub> has the highest percentage of face-sharing RuO<sub>6</sub> octahedra and, therefore, the strongest <em>d-d</em> interaction; it shows the best activity and stability in catalyzing alkaline hydrogen evolution reactions (HER). Specifically, 9<em>R</em>-BaRuO<sub>3</sub> displays a small Tafel slope of 30 mV dec<sup>−1</sup> and a low overpotential of <em>η</em><sub>10</sub> < 51 mV. This performance is attributed to its high intrinsic activity delivered by the <em>d-d</em> interaction and is intimately related to the crystal structure. The micron-sized 9<em>R</em>-BaRuO<sub>3</sub> powders are stable under industrial plasma spraying and carry a current density of 0.4 A/cm<sup>2</sup> @ 1.74 V in commercial alkaline water electrolyzers. The results on catalytic activities and crystal structure provide insight for designing better electrocatalysts for practical applications.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"226 1-2 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142384658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.checat.2024.101129
Zhiting Wang, Changqing Rao, Hanmin Huang
The dicarbofunctionalization of alkynes with unsaturated electrophiles and alkyl halides proceeding via the oxidative cyclometallation pathway offers a promising tool to synthesize multi-substituted alkenes. However, the inherent formation of cyclometallic intermediates is limited to the formation of cis products. We demonstrate here that the anti-dialkylation of alkynes with alkyl halides and unsaturated iminium is accessible via sequential radical addition promoted by cobalt electron-shuttle catalysis. This process exhibits broad substrate scope and high functional group compatibility, providing a straightforward and efficient approach to densely functionalized trans-alkenes. The newly developed facile hydrodefluorination enabled by simple LiAlH4 further enhances the practicability of this procedure. Mechanistic studies revealed that bypassing the formation of alkenyl metal species is beneficial to obtain excellent stereoselectivity.
{"title":"Electron-shuttle catalysis enables regioselective and stereospecific dialkylation of alkynes","authors":"Zhiting Wang, Changqing Rao, Hanmin Huang","doi":"10.1016/j.checat.2024.101129","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101129","url":null,"abstract":"The dicarbofunctionalization of alkynes with unsaturated electrophiles and alkyl halides proceeding via the oxidative cyclometallation pathway offers a promising tool to synthesize <em>multi</em>-substituted alkenes. However, the inherent formation of cyclometallic intermediates is limited to the formation of <em>cis</em> products. We demonstrate here that the <em>anti</em>-dialkylation of alkynes with alkyl halides and unsaturated iminium is accessible via sequential radical addition promoted by cobalt electron-shuttle catalysis. This process exhibits broad substrate scope and high functional group compatibility, providing a straightforward and efficient approach to densely functionalized <em>trans</em>-alkenes. The newly developed facile hydrodefluorination enabled by simple LiAlH<sub>4</sub> further enhances the practicability of this procedure. Mechanistic studies revealed that bypassing the formation of alkenyl metal species is beneficial to obtain excellent stereoselectivity.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"1 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142384659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.checat.2024.101128
Po-Wei Huang, Danae A. Chipoco Haro, Hakhyeon Song, Andrew J. Medford, Marta C. Hatzell
The photocatalytic nitrogen reduction reaction (pNRR) for ammonia (NH3) production is often discussed as a sustainable alternative to the thermocatalytic Haber-Bosch process. One of the main challenges in pNRR research is the lack of reliable detection of photochemically produced NH3 since NH3 concentrations are often low and nitrogen-containing impurities may be present. Here, we identify three key sources of contamination (feed gases, catalyst precursors, and hole scavengers) and systematically quantify and reduce the contamination. We developed a custom photoreactor setup to minimize contamination and benchmarked three photocatalysts previously reported to be active toward pNRR. Our results indicate that the pNRR rates of all three catalysts under benchmarking conditions are much lower than previously reported and in some cases have negligible activity. We suggest essential control experiments to contribute to the standardization of NH3 measurements in the pNRR field and to help the field elucidate the photoactivity of catalysts toward pNRR.
{"title":"Benchmarking photocatalysts for dinitrogen photoreduction reaction","authors":"Po-Wei Huang, Danae A. Chipoco Haro, Hakhyeon Song, Andrew J. Medford, Marta C. Hatzell","doi":"10.1016/j.checat.2024.101128","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101128","url":null,"abstract":"The photocatalytic nitrogen reduction reaction (pNRR) for ammonia (NH<sub>3</sub>) production is often discussed as a sustainable alternative to the thermocatalytic Haber-Bosch process. One of the main challenges in pNRR research is the lack of reliable detection of photochemically produced NH<sub>3</sub> since NH<sub>3</sub> concentrations are often low and nitrogen-containing impurities may be present. Here, we identify three key sources of contamination (feed gases, catalyst precursors, and hole scavengers) and systematically quantify and reduce the contamination. We developed a custom photoreactor setup to minimize contamination and benchmarked three photocatalysts previously reported to be active toward pNRR. Our results indicate that the pNRR rates of all three catalysts under benchmarking conditions are much lower than previously reported and in some cases have negligible activity. We suggest essential control experiments to contribute to the standardization of NH<sub>3</sub> measurements in the pNRR field and to help the field elucidate the photoactivity of catalysts toward pNRR.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"4 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.checat.2024.101127
Andrej Ribar, Martin Pfeiffer, Bernd Nidetzky
C-nucleosides are important targets for synthesis as anti-infective agents and building blocks for therapeutic nucleic acids. Here, we show phosphorylation-condensation cascade reaction to produce pseudouridine 5′-phosphate (Ψ5P) from d-ribose (Rib) and uracil. Rib (∼1.0 M) was phosphorylated at O5 in aqueous acetyl phosphate (1.15 M) via ATP (5 mM) by coupled kinases. Using Ψ5P C-glycosidase, Rib5P intermediate (≥90% yield) was reacted with the mole equivalent of uracil, supplied as a solid, to give Ψ5P in quantitative yield. One-pot reaction optimized for reagent composition, automated pH control, and solid-liquid mass transfer yielded ∼2.2 g Ψ5P (productivity: 38 g/L/h) from 10-mL volume. Synthetic flexibility of the cascade reaction was shown with other pentoses (d-arabinose, 2-deoxy-Rib, d-xylose) and analogs of uracil (6-amino, 2-thio, 4-thio). Collectively, we show massive intensification (≥50-fold) of the pentose phosphorylation as well as the C–C bond-forming condensation step of the overall multienzyme cascade transformation for efficient C-nucleoside (monophosphate) synthesis.
{"title":"Phosphorylation-condensation cascade for biocatalytic synthesis of C-nucleosides","authors":"Andrej Ribar, Martin Pfeiffer, Bernd Nidetzky","doi":"10.1016/j.checat.2024.101127","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101127","url":null,"abstract":"<em>C</em>-nucleosides are important targets for synthesis as anti-infective agents and building blocks for therapeutic nucleic acids. Here, we show phosphorylation-condensation cascade reaction to produce pseudouridine 5′-phosphate (Ψ5P) from <span>d</span>-ribose (Rib) and uracil. Rib (∼1.0 M) was phosphorylated at O5 in aqueous acetyl phosphate (1.15 M) via ATP (5 mM) by coupled kinases. Using Ψ5P <em>C</em>-glycosidase, Rib5P intermediate (≥90% yield) was reacted with the mole equivalent of uracil, supplied as a solid, to give Ψ5P in quantitative yield. One-pot reaction optimized for reagent composition, automated pH control, and solid-liquid mass transfer yielded ∼2.2 g Ψ5P (productivity: 38 g/L/h) from 10-mL volume. Synthetic flexibility of the cascade reaction was shown with other pentoses (<span>d</span>-arabinose, 2-deoxy-Rib, <span>d</span>-xylose) and analogs of uracil (6-amino, 2-thio, 4-thio). Collectively, we show massive intensification (≥50-fold) of the pentose phosphorylation as well as the C–C bond-forming condensation step of the overall multienzyme cascade transformation for efficient <em>C</em>-nucleoside (monophosphate) synthesis.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"40 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.checat.2024.101126
Meihui Guan, Lihan Zhu, Yue Wang, Ge Zhang, Huanran Miao, Bei Chen, Qian Zhang
Catalytic asymmetric hydroetherification of alkenes constitutes an efficient strategy toward enantioenriched oxygenated building blocks from readily available starting materials. However, the enantioselective intermolecular transformation of simple alkenes is particularly underdeveloped. Here, a Co(III)-hydride-mediated enantioselective olefin hydroetherification through radical-polar crossover H atom transfer has been described, with cyclic 1,3-diketone derivatives as O nucleophilic partners. This practical method is applicable for both styrenes and aliphatic alkenes with good functional group tolerance, enabling facile access to structurally diverse chiral vinylogous ester derivatives with excellent regio-, chemo-, and enantioselectivity. Theoretical studies have shown that the formation of alkyl Co(III) intermediates and the SN2-substitution of alkyl Co(IV) with nucleophiles have an effect on the stereoselectivity of the products. Additionally, the O–H···π interaction between the –OH moiety of substrate moiety and salen ligand plays a crucial role in determining unique asymmetric C–O bond chemoselectivity compared to the disfavored steric hindrance in C–C bond construction.
{"title":"Cobalt-catalyzed enantioselective hydroetherification of alkenes and symmetric 1,3-diketones","authors":"Meihui Guan, Lihan Zhu, Yue Wang, Ge Zhang, Huanran Miao, Bei Chen, Qian Zhang","doi":"10.1016/j.checat.2024.101126","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101126","url":null,"abstract":"Catalytic asymmetric hydroetherification of alkenes constitutes an efficient strategy toward enantioenriched oxygenated building blocks from readily available starting materials. However, the enantioselective intermolecular transformation of simple alkenes is particularly underdeveloped. Here, a Co(III)-hydride-mediated enantioselective olefin hydroetherification through radical-polar crossover H atom transfer has been described, with cyclic 1,3-diketone derivatives as O nucleophilic partners. This practical method is applicable for both styrenes and aliphatic alkenes with good functional group tolerance, enabling facile access to structurally diverse chiral vinylogous ester derivatives with excellent regio-, chemo-, and enantioselectivity. Theoretical studies have shown that the formation of alkyl Co(III) intermediates and the S<sub>N</sub>2-substitution of alkyl Co(IV) with nucleophiles have an effect on the stereoselectivity of the products. Additionally, the O–H···π interaction between the –OH moiety of substrate moiety and salen ligand plays a crucial role in determining unique asymmetric C–O bond chemoselectivity compared to the disfavored steric hindrance in C–C bond construction.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"44 Suppl 1 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.checat.2024.101123
Jian Yu, Guang-Hui Lu, Yi He, Min-Hua Zong, Ning Li
C4 chemicals such as succinic acid and γ-butyrolactone are important industrial feedstocks. In this work, we present a flexible photoenzymatic route toward biobased C4 chemicals from furfural via fumaric semialdehyde (FSA). The high reactivity and plasticity of multifunctionalized FSA allow facile production of various C4 chemicals by slightly modifying multienzymatic cascades. Seven valuable C4 chemicals were obtained by sequential photoenzymatic and multienzymatic catalysis in 73%–92% yields. Synergistic catalysis by meso-tetra(4-carboxyphenyl)porphyrin (TCPP) and a basic resin enabled direct conversion of furfural into FSA. In photoenzymatic (E)-4-hydroxycrotonic acid synthesis involving TCPP, a space-time yield of up to 1.7 g L−1 h−1 and a total turnover number of 94,000 for an enzyme were achieved. Besides, gram-scale synthesis of four C4 chemicals was implemented in 60%–88% isolated yields. The photoenzymatic route centering FSA may work as an alternative route for the production of valuable C4 chemicals.
{"title":"Photoenzymatic synthesis of C4 chemicals from biomass-derived furfural via fumaric semialdehyde","authors":"Jian Yu, Guang-Hui Lu, Yi He, Min-Hua Zong, Ning Li","doi":"10.1016/j.checat.2024.101123","DOIUrl":"https://doi.org/10.1016/j.checat.2024.101123","url":null,"abstract":"C4 chemicals such as succinic acid and γ-butyrolactone are important industrial feedstocks. In this work, we present a flexible photoenzymatic route toward biobased C4 chemicals from furfural via fumaric semialdehyde (FSA). The high reactivity and plasticity of multifunctionalized FSA allow facile production of various C4 chemicals by slightly modifying multienzymatic cascades. Seven valuable C4 chemicals were obtained by sequential photoenzymatic and multienzymatic catalysis in 73%–92% yields. Synergistic catalysis by meso-tetra(4-carboxyphenyl)porphyrin (TCPP) and a basic resin enabled direct conversion of furfural into FSA. In photoenzymatic (<em>E</em>)-4-hydroxycrotonic acid synthesis involving TCPP, a space-time yield of up to 1.7 g L<sup>−1</sup> h<sup>−1</sup> and a total turnover number of 94,000 for an enzyme were achieved. Besides, gram-scale synthesis of four C4 chemicals was implemented in 60%–88% isolated yields. The photoenzymatic route centering FSA may work as an alternative route for the production of valuable C4 chemicals.","PeriodicalId":53121,"journal":{"name":"Chem Catalysis","volume":"220 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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