Sustainable Aerobic Allylic C–H Bond Oxidation with Heterogeneous Iron Catalyst

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(4), P. 2769 - 2778

Published: Jan. 19, 2024

Emerging techniques are revolutionizing the realm of chemical synthesis by introducing new avenues for C–H bond functionalization, which have been exploited pharmaceuticals, natural compounds, and functional materials. Allylic oxidation alkenes serves as possibly most employed functionalization reaction. However, sustainable selective approaches remain scarce, majority existing conditions still hinge on hazardous oxidants or costly metal catalysts. In this context, we introduce a heterogeneous iron catalyst that addresses above-mentioned concerns showcasing aerobic steroids, terpenes, simple olefins to corresponding enone products. This novel method provides powerful tool arsenal allylic while minimizing environmental concerns.

Language: Английский

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Carbon-carbon triple bond cleavage and reconstitution to achieve aryl amidation using nitrous acid esters

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 24, 2025

C–C bond cleavage and recombination provide an efficient strategy for the modification reconstruction of molecule structures. Herein, we present a method achieving amidation aryl C(sp2)–H through triple with involvement nitrous acid esters. This marks instance precise controlled stepwise bond, offering fresh perspective such bonds. Nitrous ester serves as both radical source hydrogen atom transfer (HAT) reagent to functionalize utilize two carbon atoms bond. The alkoxy captures from or N-hydroxyl induce 1,3-oxygen migration, which is crucial subsequent molecular authors report achieve bonds by participation

Language: Английский

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Cobalt-Catalyzed Acceptorless Dehydrogenation of Primary Amines to Nitriles

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(17), P. 11801 - 11810

Published: April 16, 2024

The direct double dehydrogenation from primary amines to nitriles without an oxidant or hydrogen acceptor is both intriguing and challenging. In this paper, we describe a non-noble metal catalyst capable of realizing such transformation with high efficiency. A cobalt-centered N,N-bidentate complex was designed employed as metal–ligand cooperative catalyst. Detailed kinetic studies, control experiments, DFT calculations revealed the crucial hydride transfer, proton evolution processes. Finally, tandem outer-sphere/inner-sphere mechanism proposed for through imine intermediate.

Language: Английский

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Multicomponent Reductive Coupling for Selective Access to Functional γ-Lactams by a Single-Atom Cobalt Catalyst

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: March 21, 2024

Despite their significant importance to numerous fields, the difficulties in direct and diverse synthesis of α-hydroxy-γ-lactams pose substantial obstacles practical applications. Here, we designed a nitrogen TiO2 co-doped graphitic carbon-supported material with atomically dispersed cobalt sites (CoSA-N/NC-TiO2), which was successfully applied as multifunctional catalyst establish general method for construction from cheap abundant nitro(hetero)arenes, aldehydes, H2O alkynoates. The striking features operational simplicity, broad substrate functionality compatibility (>100 examples), high step atom efficiency, good selectivity, exceptional reusability highlight practicality this new catalytic transformation. Mechanistic studies reveal that active CoN4 species dopants exhibit synergistic effect on formation key acid-masked nitrones; subsequent nucleophilic addition alkynoates followed by successive reduction, alkenyl hydration, intramolecular ester ammonolysis delivers desired products. In work, concept reduction interruption leading reaction route will open door further develop useful transformations rational design.

Language: Английский

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Single-Atom Fe-Catalyzed Acceptorless Dehydrogenative Coupling to Quinolines

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 23338 - 23347

Published: Aug. 6, 2024

A single-atom iron catalyst was found to exhibit exceptional reactivity in acceptorless dehydrogenative coupling for quinoline synthesis, outperforming known homogeneous and nanocatalyst systems. Detailed characterizations, including aberration-corrected HAADF-STEM, XANES, EXAFS, jointly confirmed the presence of atomically dispersed centers. Various functionalized quinolines were efficiently synthesized from different amino alcohols a range ketones or alcohols. The achieved turnover number (TON) up 10

Language: Английский

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A Click Chemistry Strategy Toward Spin‐Polarized Transition‐Metal Single Site Catalysts for Dynamic Probing of Sulfur Redox Electrocatalysis

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 17, 2024

Abstract Catalytic conversion of lithium polysulfides (LiPSs) is a crucial approach to enhance the redox kinetics and suppress shuttle effect in lithium–sulfur (Li–S) batteries. However, roles typical heterogenous catalyst cannot be easily identified due its structural complexity. Compared with distinct sites single atom catalysts (SACs), each active site (SSCs) identical uniform their spatial energy, binding mode, coordination sphere, etc. Benefiting from well‐defined structure, iron phthalocyanine (FePc) covalently clicked onto CuO nanosheet prepare low spin‐state Fe SSCs as model for Li–S electrochemistry. The periodic polarizability evolution Fe‐N bonding probed during sulfur reaction by situ Raman spectra. Theoretical analysis shows decreased d‐band center gap (Δd) delocalization d xz /d yz after axial click confinement. Consequently, batteries exhibit capacity decay rate 0.029% per cycle at 2 C. universality this methodological demonstrated series M (M = Mn, Co, Ni) similar variation electronic configuration. This work provides guidance design efficient electrocatalysis

Language: Английский

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Atomically Dispersed Cu Atoms Anchored on N-Doped Porous Carbon as an Efficient Catalyst for C–C Bond Cleavage of Ketones toward Esters

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 1704 - 1714

Published: Jan. 16, 2025

Efficient and selective cleavage functionalization of C–C bonds is critical significance in fine chemistry lignocellulosic biomass valorization, yet it still challenging due to their inert nature. In the present work, we report an atomically dispersed Cu catalyst encapsulated N-doped porous carbon (Cu@NC-900) through a facile method using metal–organic frameworks (MOFs) as precursors, where atoms were chelated stabilized by N species. The resulting exhibited good performance for oxidative toward esters, giving 98.6% yield methyl benzoate with complete conversion acetophenone under base-free conditions. Further, Cu@NC-900 was efficient wide range ketones, including (hetero)aryl ketones or alkyl corresponding esters. Experiments demonstrated that highly sites incorporation species, well rich pore structures, contributed high activity, selectivity, stability. Theoretical calculations further attributed activity oxidation state formed electron loss isolated atoms.

Language: Английский

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Biomass‐Derived Cu‐Catalyzed General C—X (X = C, N, O) Bond Formation: Carbenoid Insertion Reactions of C—H, N—H, O—H Bond and Late‐stage Functionalization of Drug Molecules^†

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 7, 2025

Comprehensive Summary The development of sustainable and efficient catalytic systems for the formation C—C, C—N, C—O bonds is a fundamental goal in modern synthetic chemistry. We present biomass‐derived Cu/Chitosan‐800 catalyst that facilitates range carbenoid insertion reactions into C—H, N—H, O—H bonds. This demonstrates remarkable activity, enabling functionalization diverse substrates, including late‐stage modification drug molecules with up to 95% yield good recyclability. Our findings highlight catalyst's potential advancing environmentally friendly chemical transformations, offering promising tool pharmaceutical synthesis organic synthesis.

Language: Английский

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Reduction-Interrupted Tandem Reaction for General Synthesis of Functional Amino Acids by a Heterogeneous Cobalt Catalyst

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 11, 2025

Despite their significant importance in numerous fields, the challenges direct and diverse synthesis of γ-amino-α-hydroxybutyric acids (AHBAs) pose substantial obstacles to explore functions. Here, by preparation a N-doped carbon-supported bifunctional cobalt catalyst (Co-DAPhen/C), it was applied develop reductive tandem reaction for general AHBA derivatives from cheap abundant nitroarenes, formaldehyde, acrylates. This catalytic three-component features broad substrate functionality tolerance, an easily accessible reusable catalyst, high step atom economy. The active Co sites are involved mild reduction processes with formic acid, whereas carbon support enriches HCHO acrylates physical adsorption, thus favoring capture hydroxylamine nitrone intermediates via condensation 1,3-dipolar cycloaddition, respectively. Such metal–support synergy interrupts conventional nitroarenes into anilines results novel route. In this work, concept merging effective intermediate transformations is anticipated more useful reactions rational design.

Language: Английский

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Oxidative amination by nitrogen atom insertion into carbon-carbon double bonds

Science, Journal Year: 2025, Volume and Issue: 387(6738), P. 1108 - 1114

Published: March 6, 2025

The synthesis of nitrogen-containing molecules through carbon-nitrogen (C-N) bond formation is critical for the discovery and preparation medicines, agrochemicals, materials. Here, we report direct insertion a nitrogen atom into unactivated carbon-carbon double bonds to access aza-allenium intermediates, which can be converted either nitriles or amidine products, depending on initial alkene substitution pattern. This operationally simple highly functionally compatible reaction works wide range alkenes. PIFA, commercially available inexpensive hypervalent iodine reagent, key this reactivity. Our mechanistic proposal supported by chemical trapping experiments, concomitantly demonstrate utility our method valuable N-heterocycles. Additionally, used as general strategy synthesizing amides amines, well 15N-labeled molecules.

Language: Английский

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