The free C2-OH group of glycosyl donors is generally viewed as a liability in glycosylation because it can act as a competing nucleophile and compromise stereocontrol. Here, we show that this functionality can instead be harnessed as a programmable stereochemical element in a catalyst-controlled stereodivergent glycosylation. A single β-configured 2-hydroxy glycosyl 8-alkynyl-1-naphthoate donor was found to deliver either β- or α-glycosides simply by changing the gold(I) catalyst system. Triflate-based catalysts promoted highly β-selective glycosylation, whereas bistriflimide-based conditions enabled complementary α-selective glycosylation from the same donor. The method is applicable to a range of carbohydrate and noncarbohydrate acceptors and enables the programmable assembly of glucooligosaccharides bearing β-(1→6), α-(1→6), and alternating α/β-(1→6) linkages from a common donor platform. Mechanistic studies, including intermediate characterization, variable-temperature NMR experiments, computational analysis, and control glycosylations with the corresponding 2-O-Bn donor, reveal distinct roles of the donor 2-OH group in the two stereochemical manifolds.
{"title":"Repurposing a Donor 2-OH Group for Catalyst-Controlled Stereodivergent Glycosylation","authors":"Yingjie Wang,Yu-Cheng Peng,Qian Zhang,Liran Yang,Qing Wang,Kai Chen,Yugen Zhu","doi":"10.1021/acscatal.6c07304","DOIUrl":"https://doi.org/10.1021/acscatal.6c07304","url":null,"abstract":"The free C2-OH group of glycosyl donors is generally viewed as a liability in glycosylation because it can act as a competing nucleophile and compromise stereocontrol. Here, we show that this functionality can instead be harnessed as a programmable stereochemical element in a catalyst-controlled stereodivergent glycosylation. A single β-configured 2-hydroxy glycosyl 8-alkynyl-1-naphthoate donor was found to deliver either β- or α-glycosides simply by changing the gold(I) catalyst system. Triflate-based catalysts promoted highly β-selective glycosylation, whereas bistriflimide-based conditions enabled complementary α-selective glycosylation from the same donor. The method is applicable to a range of carbohydrate and noncarbohydrate acceptors and enables the programmable assembly of glucooligosaccharides bearing β-(1→6), α-(1→6), and alternating α/β-(1→6) linkages from a common donor platform. Mechanistic studies, including intermediate characterization, variable-temperature NMR experiments, computational analysis, and control glycosylations with the corresponding 2-O-Bn donor, reveal distinct roles of the donor 2-OH group in the two stereochemical manifolds.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"94 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218865","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}
Photocatalytic activation of inert chemical bonds represents a promising route for selective conversion of organic molecules such as acetonitrile (CH3CN) into value-added products. However, as the most common reactive oxygen species, •OH radicals are nonselective and usually lead to overoxidation reactions, making it difficult to realize the target product with both high activity and selectivity in the photocatalytic system. Here, we demonstrate that, through oxygen vacancy (Vo) engineering, selective CH3CN conversion into HCOOH is enabled over a WO3 photocatalyst under mild conditions. Under simulated solar irradiation, the as-prepared Vo-rich WO3 nanosheets display notable photocatalytic CH3CN conversion performance, with a HCOOH yield rate of 8.8 mmol g–1 h–1 and a selectivity as high as 86.5%. In combination of various in situ spectroscopic techniques, it is revealed that the Vo constructs a coupling match between of •OH radicals and •CH2CN intermediates on the WO3 photocatalyst surface, which facilitates the selective conversion of CH3CN into HCOOH while preventing its overoxidation. This work extends the conversion pathway of CH3CN in a photocatalytic route and provides deeper insight into the selective conversion of inert molecules.
{"title":"Solar-Driven Highly Active and Selective Conversion of Acetonitrile to Formic Acid over Oxygen Vacancy Engineered Tungsten Oxide","authors":"Yuewen Sun,Shenghe Si,Yuyin Mao,Honggang Zhang,Lingtong Lin,Zeyan Wang,Peng Wang,Zhaoke Zheng,Yuanyuan Liu,Baibiao Huang,Hefeng Cheng","doi":"10.1021/acscatal.6c05158","DOIUrl":"https://doi.org/10.1021/acscatal.6c05158","url":null,"abstract":"Photocatalytic activation of inert chemical bonds represents a promising route for selective conversion of organic molecules such as acetonitrile (CH3CN) into value-added products. However, as the most common reactive oxygen species, •OH radicals are nonselective and usually lead to overoxidation reactions, making it difficult to realize the target product with both high activity and selectivity in the photocatalytic system. Here, we demonstrate that, through oxygen vacancy (Vo) engineering, selective CH3CN conversion into HCOOH is enabled over a WO3 photocatalyst under mild conditions. Under simulated solar irradiation, the as-prepared Vo-rich WO3 nanosheets display notable photocatalytic CH3CN conversion performance, with a HCOOH yield rate of 8.8 mmol g–1 h–1 and a selectivity as high as 86.5%. In combination of various in situ spectroscopic techniques, it is revealed that the Vo constructs a coupling match between of •OH radicals and •CH2CN intermediates on the WO3 photocatalyst surface, which facilitates the selective conversion of CH3CN into HCOOH while preventing its overoxidation. This work extends the conversion pathway of CH3CN in a photocatalytic route and provides deeper insight into the selective conversion of inert molecules.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"64 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218867","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}
In heterogeneous catalysis, the electronic structures of catalysts' active sites are modified to optimize intermediate binding and bond activation for achieving high reaction activity. However, studies on regulating the atomic structures of catalytic materials to enhance the configurational diversity of adsorbed intermediates remain scarce. Herein, we demonstrate that engineering under-coordinated active site motifs enables an entropy-enhanced catalytic mechanism that harnesses the configurational freedom of surface intermediates to improve reaction rates at reduced temperatures. Using CO2 methanation as a model reaction, we identified that under-coordinated Ru2+−oxygen vacancy (Ru2+−VO) sites promote delocalized catalyst−intermediate interactions and reduce the reaction energy barrier. Stable Ru2+−VO sites were created on Au nanoparticle-grafted (RuOx)a(CeOy)b solid-solution nanorods through plasmonic effects under reducing conditions. Eyring plot analysis revealed an activation entropy gain of TΔΔS‡ ≈ 12 kJ mol−1 for CO2 methanation at 300 °C, in situ spectroscopy revealed a *HCOO-mediated pathway, and ab initio molecular dynamics simulations indicated a 0.22 eV free-energy barrier for *HCOO formation on Ru2+−VO motifs. A CH4 production rate of 550 mmol gcat−1 h−1 with >98% selectivity and >280 h stability at 300 °C was achieved at a high gas hourly space velocity of 40,000−100,000 mL gcat−1 h−1. The findings provide a conceptual framework beyond adsorption energy optimization in catalyst design, showing that configurational entropy is a tunable descriptor for enhancing catalytic kinetics.
{"title":"Entropy-Enhanced Catalysis Accelerates Low-Temperature CO2 Methanation via Intermediate Delocalization at Under-Coordinated Ru2+−VO Sites","authors":"Haoyang Jiang,Hiroaki Kaneko,Renjie Zhou,Yueren Liu,Chenxi Guo,Masahiro Miyauchi,Miao Zhong","doi":"10.1021/acscatal.6c06063","DOIUrl":"https://doi.org/10.1021/acscatal.6c06063","url":null,"abstract":"In heterogeneous catalysis, the electronic structures of catalysts' active sites are modified to optimize intermediate binding and bond activation for achieving high reaction activity. However, studies on regulating the atomic structures of catalytic materials to enhance the configurational diversity of adsorbed intermediates remain scarce. Herein, we demonstrate that engineering under-coordinated active site motifs enables an entropy-enhanced catalytic mechanism that harnesses the configurational freedom of surface intermediates to improve reaction rates at reduced temperatures. Using CO2 methanation as a model reaction, we identified that under-coordinated Ru2+−oxygen vacancy (Ru2+−VO) sites promote delocalized catalyst−intermediate interactions and reduce the reaction energy barrier. Stable Ru2+−VO sites were created on Au nanoparticle-grafted (RuOx)a(CeOy)b solid-solution nanorods through plasmonic effects under reducing conditions. Eyring plot analysis revealed an activation entropy gain of TΔΔS‡ ≈ 12 kJ mol−1 for CO2 methanation at 300 °C, in situ spectroscopy revealed a *HCOO-mediated pathway, and ab initio molecular dynamics simulations indicated a 0.22 eV free-energy barrier for *HCOO formation on Ru2+−VO motifs. A CH4 production rate of 550 mmol gcat−1 h−1 with >98% selectivity and >280 h stability at 300 °C was achieved at a high gas hourly space velocity of 40,000−100,000 mL gcat−1 h−1. The findings provide a conceptual framework beyond adsorption energy optimization in catalyst design, showing that configurational entropy is a tunable descriptor for enhancing catalytic kinetics.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"11 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218863","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 : 2026-10-19DOI: 10.1021/acscatal.6c05074
Fengxi Li,Shenhan Xie,Xinjia Yu,Meijiao Gao,Qi Sun,Chuang Du,Zhi Wang,Lei Wang
The asymmetric construction of nonadjacent stereocenters in a single catalytic system remains a significant challenge due to the difficulty in controlling stereochemical relay between sequential transformations. Herein, we report a dual-enzyme relay catalytic system that integrates an artificial streptavidin-based copper metalloenzyme (Sav-Cu) with an engineered ketoreductase (KRED) for the one-pot synthesis of polycyclic alcohols bearing 1,3-non-adjacent stereocenters. In this relay process, the engineered SavDMase variant (S112A/K121D) catalyzes a non-natural decarboxylative Mannich reaction to establish the R-configured stereocenter in the enantioenriched ketone intermediate, which is then recognized by the engineered KREDAV mutant (S96A/Y190V) and reduced with high diastereo- and enantioselectivity to install the S-configured alcohol stereocenter, thereby furnishing the (R,S)-configured product as the dominant stereoisomer. The optimized system furnishes the products in up to 83% yield, 99% ee, and 96% de across a broad substrate scope, and is readily applicable to 2 mmol-scale synthesis. Structural analysis, docking, and molecular dynamics simulations support complementary roles of the two catalytic modules: SavDMase promotes productive organization of the Mannich step, while KREDAV stabilizes the reactive binding pose and constrains the hydride-transfer trajectory to enforce stereoselective reduction. This work demonstrates how artificial and natural enzymes can be integrated in relay catalysis to solve challenging stereochemical relay problems beyond the reach of individual biocatalysts.
{"title":"Dual-Enzyme Relay Catalysis Enables Asymmetric Construction of Nonadjacent Stereocenters in Polycyclic Alcohols","authors":"Fengxi Li,Shenhan Xie,Xinjia Yu,Meijiao Gao,Qi Sun,Chuang Du,Zhi Wang,Lei Wang","doi":"10.1021/acscatal.6c05074","DOIUrl":"https://doi.org/10.1021/acscatal.6c05074","url":null,"abstract":"The asymmetric construction of nonadjacent stereocenters in a single catalytic system remains a significant challenge due to the difficulty in controlling stereochemical relay between sequential transformations. Herein, we report a dual-enzyme relay catalytic system that integrates an artificial streptavidin-based copper metalloenzyme (Sav-Cu) with an engineered ketoreductase (KRED) for the one-pot synthesis of polycyclic alcohols bearing 1,3-non-adjacent stereocenters. In this relay process, the engineered SavDMase variant (S112A/K121D) catalyzes a non-natural decarboxylative Mannich reaction to establish the R-configured stereocenter in the enantioenriched ketone intermediate, which is then recognized by the engineered KREDAV mutant (S96A/Y190V) and reduced with high diastereo- and enantioselectivity to install the S-configured alcohol stereocenter, thereby furnishing the (R,S)-configured product as the dominant stereoisomer. The optimized system furnishes the products in up to 83% yield, 99% ee, and 96% de across a broad substrate scope, and is readily applicable to 2 mmol-scale synthesis. Structural analysis, docking, and molecular dynamics simulations support complementary roles of the two catalytic modules: SavDMase promotes productive organization of the Mannich step, while KREDAV stabilizes the reactive binding pose and constrains the hydride-transfer trajectory to enforce stereoselective reduction. This work demonstrates how artificial and natural enzymes can be integrated in relay catalysis to solve challenging stereochemical relay problems beyond the reach of individual biocatalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"16 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218864","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 : 2026-10-19DOI: 10.1021/acscatal.6c04731
Mahdi Hosseinpour,Thomas F. Winterstein,Benjamin Pichler,Hans Krammer,Bernhard Klötzer,Simon Penner
We investigate the interplay between carbon accumulation and redox-driven deactivation pathways in cerium-containing nickel (NiCe) and palladium (PdCe) bimetallic precursor materials upon eventual decomposition into a Ni- or Pd-ceria interfacial system during dry reforming of methane (DRM). By probing defined intermediate states, information from surface electronic structure, morphology, and bulk structure to track structural and chemical changes across several reaction, deactivation, and CO2 titration cycles is combined to identify how carbon accumulation, oxygen transfer, and dynamic metal–ceria interfacial interactions evolve under DRM reaction conditions. Despite their similar cerium-containing precursor architecture and surface composition, the two systems allow studying two detrimental deactivation processes. Bimetallic NiCe decomposes more readily into a Ni-ceria interface, where carbon formation is progressively suppressed. Loss of activity is a result of oxidation of Ni particles mediated by enhanced oxygen transfer from ceria. In contrast, bimetallic PdCe is much more decomposition-resistant, and the localized Pd-ceria interface exhibits high activity throughout multiple DRM cycles, even in the presence of substantial carbon deposition and filamentous carbon growth. The results demonstrate an intrinsic coupling between carbon accumulation and oxygen transfer to the metallic component, with carbon acting as a competing sink for reactive oxygen species. We emphasize the significance of dynamic interfacial structures and show that ceria-mediated oxygen transfer produces contrasting, metal-dependent catalytic outcomes. Whereas in NiCe, efficient oxygen delivery suppresses carbon accumulation, but progressively oxidizes Ni and diminishes methane activation, in PdCe, carbon generation outpaces oxygen-mediated removal, yielding a carbon-rich yet catalytically persistent surface.
{"title":"The Two Opposite Faces of Ceria as Redox Mediator in Methane Dry Reforming","authors":"Mahdi Hosseinpour,Thomas F. Winterstein,Benjamin Pichler,Hans Krammer,Bernhard Klötzer,Simon Penner","doi":"10.1021/acscatal.6c04731","DOIUrl":"https://doi.org/10.1021/acscatal.6c04731","url":null,"abstract":"We investigate the interplay between carbon accumulation and redox-driven deactivation pathways in cerium-containing nickel (NiCe) and palladium (PdCe) bimetallic precursor materials upon eventual decomposition into a Ni- or Pd-ceria interfacial system during dry reforming of methane (DRM). By probing defined intermediate states, information from surface electronic structure, morphology, and bulk structure to track structural and chemical changes across several reaction, deactivation, and CO2 titration cycles is combined to identify how carbon accumulation, oxygen transfer, and dynamic metal–ceria interfacial interactions evolve under DRM reaction conditions. Despite their similar cerium-containing precursor architecture and surface composition, the two systems allow studying two detrimental deactivation processes. Bimetallic NiCe decomposes more readily into a Ni-ceria interface, where carbon formation is progressively suppressed. Loss of activity is a result of oxidation of Ni particles mediated by enhanced oxygen transfer from ceria. In contrast, bimetallic PdCe is much more decomposition-resistant, and the localized Pd-ceria interface exhibits high activity throughout multiple DRM cycles, even in the presence of substantial carbon deposition and filamentous carbon growth. The results demonstrate an intrinsic coupling between carbon accumulation and oxygen transfer to the metallic component, with carbon acting as a competing sink for reactive oxygen species. We emphasize the significance of dynamic interfacial structures and show that ceria-mediated oxygen transfer produces contrasting, metal-dependent catalytic outcomes. Whereas in NiCe, efficient oxygen delivery suppresses carbon accumulation, but progressively oxidizes Ni and diminishes methane activation, in PdCe, carbon generation outpaces oxygen-mediated removal, yielding a carbon-rich yet catalytically persistent surface.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"13 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218866","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 : 2026-10-19DOI: 10.1021/acscatal.6c07295
Shengwei Sun,Erik N. A. Sundén,Marcus Moldenhauer,Diana Bernin,Uwe T. Bornscheuer,Minna Hakkarainen,Per-Olof Syrén
The complex structure of polyurethanes (PURs) presents a major barrier to their efficient recycling. Here, we report a chemoenzymatic cascade that enables the simultaneous recycling and upcycling of PUR through rapid alkaline pretreatment followed by urethanase-catalyzed depolymerization. Using in-house-synthesized model polyether- and polyester-based PUR elastomers, we establish that soft-segment chemistry dictates the composition, morphology, and accessibility of the pretreated residues, thereby governing the efficiency of the subsequent enzymatic hydrolysis. This insight enabled translation of the cascade to a commercial PUR elastomer, achieving >93% chemical conversion and recovery of up to 1 mM 4,4′-methylenedianiline (MDA) (97.2% purity), corresponding to a 40-fold increase over the nonenzymatic control, together with polyols obtained in 95% isolated yield that were directly reused for PUR synthesis. Mechanistic studies further show that alkaline pretreatment enhances substrate accessibility for the enzyme, and structural analysis of urethanase SP2 reveals a carbamate-specific hydrogen-bonding interaction that promotes urethane hydrolysis while minimizing esterase activity. The cascade was additionally applied to highly crosslinked commercial PUR foams and adhesives, demonstrating its versatility toward industrially relevant waste streams. Overall, this work establishes a mechanistically informed chemoenzymatic platform for PUR depolymerization and provides a strategy for converting chemically recalcitrant PUR waste into reusable molecular building blocks.
{"title":"Chemoenzymatic Cascade Recycling and Upcycling of Polyurethane Elastomers","authors":"Shengwei Sun,Erik N. A. Sundén,Marcus Moldenhauer,Diana Bernin,Uwe T. Bornscheuer,Minna Hakkarainen,Per-Olof Syrén","doi":"10.1021/acscatal.6c07295","DOIUrl":"https://doi.org/10.1021/acscatal.6c07295","url":null,"abstract":"The complex structure of polyurethanes (PURs) presents a major barrier to their efficient recycling. Here, we report a chemoenzymatic cascade that enables the simultaneous recycling and upcycling of PUR through rapid alkaline pretreatment followed by urethanase-catalyzed depolymerization. Using in-house-synthesized model polyether- and polyester-based PUR elastomers, we establish that soft-segment chemistry dictates the composition, morphology, and accessibility of the pretreated residues, thereby governing the efficiency of the subsequent enzymatic hydrolysis. This insight enabled translation of the cascade to a commercial PUR elastomer, achieving >93% chemical conversion and recovery of up to 1 mM 4,4′-methylenedianiline (MDA) (97.2% purity), corresponding to a 40-fold increase over the nonenzymatic control, together with polyols obtained in 95% isolated yield that were directly reused for PUR synthesis. Mechanistic studies further show that alkaline pretreatment enhances substrate accessibility for the enzyme, and structural analysis of urethanase SP2 reveals a carbamate-specific hydrogen-bonding interaction that promotes urethane hydrolysis while minimizing esterase activity. The cascade was additionally applied to highly crosslinked commercial PUR foams and adhesives, demonstrating its versatility toward industrially relevant waste streams. Overall, this work establishes a mechanistically informed chemoenzymatic platform for PUR depolymerization and provides a strategy for converting chemically recalcitrant PUR waste into reusable molecular building blocks.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"66 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218861","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 : 2026-10-19DOI: 10.1021/acscatal.6c03365
Husain Adamji,Ilia Kevlishvili,David W. Kastner,Ralf Meyer,Yuriy Román-Leshkov,Heather J. Kulik
The selective conversion of methane to methanol remains a major challenge in catalysis, and no earth-abundant homogeneous catalyst has been demonstrated to carry out this transformation with high turnover. To explore previously synthesized complexes that might be amenable for this transformation, we start from macrocyclic ligands from experimental structures in the Cambridge Structural Database. After expanding this set of ligands with Hammett-tuning functionalization, we construct a design space of 21.9 million Mn and Fe catalysts. We employ active learning using neural network surrogate models with quantified uncertainty to efficiently identify catalysts with optimal methane-to-methanol turnover. We do this by jointly optimizing density functional theory (DFT)-computed hydrogen atom transfer (HAT) and methyl radical rebound energetics. Square planar tetraaza-based macrocycles in combination with low-spin Fe(II) or Mn(II) emerge as a privileged class of transition metal complexes within the Pareto-optimal set, with Mn(II) catalysts exhibiting balanced energetic tradeoffs of the two steps. In contrast, porphyrin catalysts exhibit favorable HAT but unfavorable rebound, and seesaw catalysts, which are not widely employed, are indeed the least favorable in our set. Full reaction coordinate analysis of representative Pareto-optimal catalysts reveals that HAT and rebound thermodynamics no longer govern turnover, which is instead determined by the stability of the metal–oxo intermediate and the rebound kinetic barrier. Nonetheless, the resulting energetic spans for these catalysts remain competitive with known earth-abundant, methane-to-methanol catalysts, underscoring the effectiveness of active learning for discovering previously unexplored, synthetically accessible catalysts and unraveling catalyst design principles for methane-to-methanol reactivity.
{"title":"Multiobjective Optimization of Synthetically Accessible Homogeneous Catalysts Reveals Tradeoffs for Methane-to-Methanol Conversion","authors":"Husain Adamji,Ilia Kevlishvili,David W. Kastner,Ralf Meyer,Yuriy Román-Leshkov,Heather J. Kulik","doi":"10.1021/acscatal.6c03365","DOIUrl":"https://doi.org/10.1021/acscatal.6c03365","url":null,"abstract":"The selective conversion of methane to methanol remains a major challenge in catalysis, and no earth-abundant homogeneous catalyst has been demonstrated to carry out this transformation with high turnover. To explore previously synthesized complexes that might be amenable for this transformation, we start from macrocyclic ligands from experimental structures in the Cambridge Structural Database. After expanding this set of ligands with Hammett-tuning functionalization, we construct a design space of 21.9 million Mn and Fe catalysts. We employ active learning using neural network surrogate models with quantified uncertainty to efficiently identify catalysts with optimal methane-to-methanol turnover. We do this by jointly optimizing density functional theory (DFT)-computed hydrogen atom transfer (HAT) and methyl radical rebound energetics. Square planar tetraaza-based macrocycles in combination with low-spin Fe(II) or Mn(II) emerge as a privileged class of transition metal complexes within the Pareto-optimal set, with Mn(II) catalysts exhibiting balanced energetic tradeoffs of the two steps. In contrast, porphyrin catalysts exhibit favorable HAT but unfavorable rebound, and seesaw catalysts, which are not widely employed, are indeed the least favorable in our set. Full reaction coordinate analysis of representative Pareto-optimal catalysts reveals that HAT and rebound thermodynamics no longer govern turnover, which is instead determined by the stability of the metal–oxo intermediate and the rebound kinetic barrier. Nonetheless, the resulting energetic spans for these catalysts remain competitive with known earth-abundant, methane-to-methanol catalysts, underscoring the effectiveness of active learning for discovering previously unexplored, synthetically accessible catalysts and unraveling catalyst design principles for methane-to-methanol reactivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"33 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218860","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 : 2026-10-19DOI: 10.1021/acscatal.6c05052
Si-Rui Zhan,Xian-Yang Zhang,Xin-Ping Wu,Xue-Qing Gong
Silver-catalyzed ethylene epoxidation is a cornerstone of the chemical industry, yet the operando surface structure of Ag nanoparticles and the identity of selectivity-governing active sites remain elusive. Here, we integrate machine learning potentials, stochastic surface walking global optimization, molecular dynamics simulation, and statistical analysis to resolve the surface landscape of Ag nanoparticles approaching experimentally relevant sizes under reaction conditions. Oxygen-induced reconstruction transforms pristine Ag facets into a globally amorphous oxide layer composed of three types of locally ordered ring motifs interspersed with structural defects. A pentagonal motif (ring5), topologically required to accommodate nanoparticle curvature and absent in conventional slab models, dominates the surface across all investigated particle sizes. Its recessed central Ag atom acts as an electronic charge buffer that weakens the critical C–Ag bond in the oxametallacycle intermediate, conferring high intrinsic ethylene oxide selectivity. Microkinetic analyses confirm that the oxygen species of ring5 regulate ethylene oxide yield, peaking at a nanoparticle oxidation degree of O/Ag ≈ 0.3–0.4. This work establishes a statistical paradigm for decoding active phases on realistic catalyst surfaces through dynamic structural ensembles.
{"title":"A Curvature-Induced Pentagonal Oxide Motif Governs Ethylene Epoxidation Selectivity on Silver Nanoparticles","authors":"Si-Rui Zhan,Xian-Yang Zhang,Xin-Ping Wu,Xue-Qing Gong","doi":"10.1021/acscatal.6c05052","DOIUrl":"https://doi.org/10.1021/acscatal.6c05052","url":null,"abstract":"Silver-catalyzed ethylene epoxidation is a cornerstone of the chemical industry, yet the operando surface structure of Ag nanoparticles and the identity of selectivity-governing active sites remain elusive. Here, we integrate machine learning potentials, stochastic surface walking global optimization, molecular dynamics simulation, and statistical analysis to resolve the surface landscape of Ag nanoparticles approaching experimentally relevant sizes under reaction conditions. Oxygen-induced reconstruction transforms pristine Ag facets into a globally amorphous oxide layer composed of three types of locally ordered ring motifs interspersed with structural defects. A pentagonal motif (ring5), topologically required to accommodate nanoparticle curvature and absent in conventional slab models, dominates the surface across all investigated particle sizes. Its recessed central Ag atom acts as an electronic charge buffer that weakens the critical C–Ag bond in the oxametallacycle intermediate, conferring high intrinsic ethylene oxide selectivity. Microkinetic analyses confirm that the oxygen species of ring5 regulate ethylene oxide yield, peaking at a nanoparticle oxidation degree of O/Ag ≈ 0.3–0.4. This work establishes a statistical paradigm for decoding active phases on realistic catalyst surfaces through dynamic structural ensembles.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"45 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218856","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 : 2026-10-19DOI: 10.1021/acscatal.6c06650
Gao-Lei Song,Qing-Bo Zhang,Xia-Wei Xu,Yu-Rou Yang,Zhao-Guo Zhang,Fa-Jun Nan
Alkenes are among the most abundant and versatile feedstocks in synthetic chemistry, yet methods for their direct and regioselective conversion into nitrogen-containing frameworks remain scarce. In particular, the direct catalytic amidination of alkenes has remained underdeveloped. Herein, we report a rhodium-catalyzed anti-Markovnikov amidination of alkenes using a stable pyridinyl formimidamide synthon. This reaction enables the direct installation of amidine moieties onto a wide range of alkenes, including styrenes, aliphatic alkenes, and challenging internal alkenes that undergo efficient chain-walking with high regioselectivity and broad functional group tolerance, accommodating unprotected amines, phenols, and halides. The resulting pyridyl amidines can be readily transformed into amides, carboxylic acids and esters, establishing a practical platform for alkene diversification. Notably, late-stage functionalization of complex bioactive molecules, including cyclosporine A, FK506, and quinine etc., provides access to previously inaccessible analogues. Mechanistic investigations, highlighted by the crystallographic capture of a key rhodium–aminopyridinyl formimidamide intermediate, provide compelling evidence for the proposed catalytic cycle. Collectively, this work not only fills a critical gap in alkene functionalization but also offers a concise and general route to high-value nitrogen-containing architectures.
{"title":"Direct Amidination of Alkenes Via C–H Activation of Pyridinyl Formimidamide Synthon","authors":"Gao-Lei Song,Qing-Bo Zhang,Xia-Wei Xu,Yu-Rou Yang,Zhao-Guo Zhang,Fa-Jun Nan","doi":"10.1021/acscatal.6c06650","DOIUrl":"https://doi.org/10.1021/acscatal.6c06650","url":null,"abstract":"Alkenes are among the most abundant and versatile feedstocks in synthetic chemistry, yet methods for their direct and regioselective conversion into nitrogen-containing frameworks remain scarce. In particular, the direct catalytic amidination of alkenes has remained underdeveloped. Herein, we report a rhodium-catalyzed anti-Markovnikov amidination of alkenes using a stable pyridinyl formimidamide synthon. This reaction enables the direct installation of amidine moieties onto a wide range of alkenes, including styrenes, aliphatic alkenes, and challenging internal alkenes that undergo efficient chain-walking with high regioselectivity and broad functional group tolerance, accommodating unprotected amines, phenols, and halides. The resulting pyridyl amidines can be readily transformed into amides, carboxylic acids and esters, establishing a practical platform for alkene diversification. Notably, late-stage functionalization of complex bioactive molecules, including cyclosporine A, FK506, and quinine etc., provides access to previously inaccessible analogues. Mechanistic investigations, highlighted by the crystallographic capture of a key rhodium–aminopyridinyl formimidamide intermediate, provide compelling evidence for the proposed catalytic cycle. Collectively, this work not only fills a critical gap in alkene functionalization but also offers a concise and general route to high-value nitrogen-containing architectures.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"56 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218858","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 : 2026-10-16Epub Date: 2026-09-28DOI: 10.1021/acscatal.6c06622
Mingzhe Ma, Meng Sun, Xiaoling Xu, Xianjie Fang
Amino aldehyde intermediates exhibit extreme chemical lability, undergoing nonproductive cyclization and polymerization in bulk solvent at rates orders of magnitude faster than enzymatic recapture. This kinetic mismatch has posed a fundamental bottleneck for transaminase-mediated stepwise diamination. Here, we resolve this long-standing challenge by discovering a previously unrecognized trans-subunit tunnel within a homodimeric transaminase that directly channels the unstable amino aldehyde intermediate between the two pyridoxal-5′-phosphate (PLP) active sites, bypassing release and rebinding. Mechanism-guided semi-rational engineering of the trans-subunit tunnel in Shimia marina transaminase (SMTA) yielded the S122G/Y324N with 1.98-fold enhanced catalytic efficiency (kcat/KM) for the stepwise diamination of 2,5-diformylfuran (DFF) to bis(aminomethyl)furan (BAMF). Stopped-flow kinetics and molecular dynamics simulations revealed that the mutations shift the tunnel from a tight-binding locked state to a dynamic-transport regime, reducing steric hindrance and optimizing electrostatic guidance to accelerate inter-subunit intermediate transit. A whole-cell cascade converting renewable 5-hydroxymethylfurfural (5-HMF) to BAMF—a promising bio-based diamine for advanced polyamides—was subjected to techno-economic (TEA) and life cycle (LCA) analyses. Together, these findings establish tunnel engineering as a generalizable paradigm for sequential biocatalytic amination. This work provides a mechanism-driven blueprint for efficient transaminase-mediated stepwise diamination, enabling biocatalytic production of bio-based diamines from renewable feedstocks.
{"title":"Direct Tunnel Channeling of Unstable Amino Aldehyde Intermediates Enables Stepwise Diamination in Transaminases","authors":"Mingzhe Ma, Meng Sun, Xiaoling Xu, Xianjie Fang","doi":"10.1021/acscatal.6c06622","DOIUrl":"10.1021/acscatal.6c06622","url":null,"abstract":"<p>Amino aldehyde intermediates exhibit extreme chemical lability, undergoing nonproductive cyclization and polymerization in bulk solvent at rates orders of magnitude faster than enzymatic recapture. This kinetic mismatch has posed a fundamental bottleneck for transaminase-mediated stepwise diamination. Here, we resolve this long-standing challenge by discovering a previously unrecognized trans-subunit tunnel within a homodimeric transaminase that directly channels the unstable amino aldehyde intermediate between the two pyridoxal-5′-phosphate (PLP) active sites, bypassing release and rebinding. Mechanism-guided semi-rational engineering of the trans-subunit tunnel in <em>Shimia marina</em> transaminase (SMTA) yielded the S122G/Y324N with 1.98-fold enhanced catalytic efficiency (<em>k</em><sub>cat</sub>/<em>K</em><sub>M</sub>) for the stepwise diamination of 2,5-diformylfuran (DFF) to bis(aminomethyl)furan (BAMF). Stopped-flow kinetics and molecular dynamics simulations revealed that the mutations shift the tunnel from a tight-binding locked state to a dynamic-transport regime, reducing steric hindrance and optimizing electrostatic guidance to accelerate inter-subunit intermediate transit. A whole-cell cascade converting renewable 5-hydroxymethylfurfural (5-HMF) to BAMF—a promising bio-based diamine for advanced polyamides—was subjected to techno-economic (TEA) and life cycle (LCA) analyses. Together, these findings establish tunnel engineering as a generalizable paradigm for sequential biocatalytic amination. This work provides a mechanism-driven blueprint for efficient transaminase-mediated stepwise diamination, enabling biocatalytic production of bio-based diamines from renewable feedstocks.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"16 20","pages":"20751–20763"},"PeriodicalIF":13.6,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090609","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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