Enantioselective Multifunctionalization with Rh Carbynoids

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(48), С. 26403 - 26411

Опубликована: Ноя. 22, 2023

Multifunctionalization from the interception of active intermediates is an attractive synthetic strategy for efficient construction complex molecular scaffolds in atom and step economic fashion. However, design reactions involving metal carbynoids that exhibit carbene/carbocation behavior currently limited, developing catalyst-controlled highly enantioselective versions poses significant challenges. In this study, we present first asymmetric trifunctionalization with rhodium carbynoids. This reaction unveils distinctive reactivity carbynoid precursor, enabling it to react simultaneously two nucleophiles one electrophile. process involves formation distinct carbene ylides alcohol/carbamate trapping ylide imine, resulting three new bonds. Furthermore, allows divergent synthesis a wide array β-amino esters high yields exceptional enantioselectivity.

Язык: Английский

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Heterogeneous Iridium-Catalyzed Carbene N–H Bond Insertion with α-Alkyl Diazo Esters

ACS Catalysis, Год журнала: 2024, Номер 14(7), С. 4690 - 4698

Опубликована: Март 13, 2024

A heterogeneous iridium single-atom site catalyst (Ir-SA) was synthesized and investigated in catalyzing the carbene insertion reaction with challenging α-alkyl diazo ester substrates. With only 0.23 mol % loading, our Ir-SA demonstrated remarkable performance N–H bond reactions involving various (hetero) aryl amines coupled esters. Notably, case of using a chiral diamino substrate two reactive sites, exhibited high selectivity toward single insertion, leading to generation class unsymmetric ligands. Further mechanism study revealed that lower activation barrier associated step, as compared either β-hydride elimination or downstream dual accounted for observed this catalyzed by Ir-SA.

Язык: Английский

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Unlocking carbene reactivity by metallaphotoredox α-elimination

Nature, Год журнала: 2024, Номер 631(8022), С. 789 - 795

Опубликована: Июнь 6, 2024

Язык: Английский

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Overview of Transition Metal Catalyzed Multicomponent Reactions Based on Trapping of Allylic Electrophiles

ChemCatChem, Год журнала: 2024, Номер 16(4)

Опубликована: Янв. 11, 2024

Abstract Multicomponent reactions provide an excellent approach toward quaternary carbon centres utilizing convergent chemical in a highly selective manner under one‐pot conditions. The reactivity of substrates and metal catalysts is carefully controlled, precluding the formation side‐products. In this context, transition catalyzed onium ylides generated via diazo precursors nucleophiles with third component (an electrophile) have garnered significant attention. Using allylic precursor as electrophilic partner provides opportunities to construct all‐carbon centres. Furthermore, presence allyl fragment multicomponent product serves pivotal handle for carrying out subsequent modifications. Several recent studies employed Rh, Pd, dual Rh/Pd catalytic systems involving alkylation that proceed synergistic or relay pathway. Although not significantly successful, few cases, asymmetric induction achieved through chiral phosphoric acids phosphine ligands. Limited substrate catalyst scope underlying mechanistic complexities posed formidable challenges, slowing advancement reactions. This review details using readily available like compounds, carbonates, (R‐OH, R‐NH 2 , etc .) forming complex organic compounds. Our primary objective discuss issues may facilitate progress field.

Язык: Английский

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Mechanism and stereoselectivity in metal and enzyme catalyzed carbene insertion into X–H and C(sp²)–H bonds

Chemical Society Reviews, Год журнала: 2024, Номер 53(22), С. 11004 - 11044

Опубликована: Янв. 1, 2024

This review provides a mechanistic overview of asymmetric Fe, Cu, Pd, Rh, Au and heme-based enzymes catalyzed carbene insertion reactions to construct C–X (X = O, N, S, etc. ) C–C bonds, focusing on the stereochemical models.

Язык: Английский

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Precise Control of Regioselective N¹ and N²-Alkylation of Benzotriazoles with α-Diazoacetates by Metalloporphyrin

Inorganic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Regioselective

Язык: Английский

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Divergent Reactivity of Azides and Diazoalkanes Toward Ferrous Complexes and Isolation of a Fe^III Carbene Radical Complex

Organometallics, Год журнала: 2025, Номер unknown

Опубликована: Янв. 9, 2025

Treatment of [(tBupyrr2pyr)Fe(OEt2)] (1-OEt2) (tBupyrr2pyr2– = 3,5-tBu2-bis(pyrrolyl)pyridine) with trimethylsilyl azide (N3SiMe3) and subsequent photolysis at 390 nm results in clean formation [(tBupyrrpyrpyrrNHSiMe3)Fe] (2) as the result a nitrene being inserted into tert-butyl C–H bond tBupyrr2pyr ligand. 1-OEt2 azidotrimethyltin (N3SnMe3), however, isolation γ-bound adduct ferrous complex, [(tBupyrr2pyr)Fe(N3SnMe3)] (1-N3SnMe3). When treated diphenyl diazomethane (Ph2CN2), complex converts to iron carbene [(tBupyrr2pyr)FeCPh2] (1-CPh2), X-ray structure revealed Fe–CPh2 length 1.964(3) Å. A room temperature magnetic moment 1-CPh2 indicates an S 2 spin state, consistent high-spin FeIII center antiferromagnetically coupled radical anion (CPh2•–). Zero-field 57Fe Mössbauer spectroscopy Fe K-edge absorption confirm this assignment. In solution, rearranges [{tBupyrrpyrC(═CPh2)-C(CMe3)═CH–C(CMe3)═N}Fe]2 (3) resulting from insertion 1-position pyrrolide arm ligand dimerization. Complex 3 possesses two FeII centers according spectroscopy, antiferromagnetic coupling between centers. Monitoring conversion by UV–vis reveals process be first order highly ordered transition state evidenced activation parameters: ΔS‡ −87.6 ± 25.8 J·mol–1·K–1 ΔH‡ 63.1 8.3 kJ·mol–1.

Язык: Английский

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A Comprehensive Mechanistic Investigation of Sustainable Carbene N-H Insertion Catalyzed by Engineered His-Ligated Heme Proteins

Catalysis Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Engineered heme proteins possess excellent biocatalytic carbene N-H insertion abilities for sustainable synthesis, and most of them have His as the Fe axial ligand. However, information on basic reaction mechanisms is limited, ground states carbenes involved in prior computational mechanistic studies are under debate. A comprehensive quantum chemical pathway study was performed model with a analogue ligand from widely used precursor ethyl diazoacetate aniline substrate. The state this calculated by high-level complete active space self-consistent field (CASSCF) approach, which shows closed-shell singlet that consistent many experimental works. Based this, DFT calculations ten main pathways were compared. Results showed favorable initial formation metal-bound ylide, followed concerted rearrangement/dissociation transition to form free enol, then underwent water-assisted proton transfer process yield final product. This prediction validated via new data using His-ligated myoglobin variants different types carbenes. Overall, first insertions, particularly neutral ligated CASSCF confirmation carbene. results also field. these build solid basis proposed mechanism facilitate future studies.

Язык: Английский

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Iron-catalyzed carbene and carbene radical cascade reactions: Mechanistic study and synthetic applications

Research Square (Research Square), Год журнала: 2025, Номер unknown

Опубликована: Янв. 30, 2025

Transition metal-catalyzed carbene transfer reactions are some of the most widely used methods that facilitate a range otherwise inaccessible chemistry. However, these advantages generally promoted by precious metal catalysts, using inexpensive and less toxic iron complexes as catalysts is under development. Moreover, surprisingly little known about mechanistic aspects, in particular structures intermediates. Herein, we report an iron-catalyzed cascade reaction alkyne-tethered diazo compounds, offering efficient approach for synthesis carbocyclic molecules with structural diversity flexibility mild conditions. Control experiments density functional theory calculations unambiguously reveal two distinct pathways catalyzed either Fe(II) or Fe(III) porphyrin complexes, which involves radical intermediates, respectively. The structure key vinyl intermediate has been determined X-ray diffraction. synthetic utility demonstrated gram-scale preparation poly-substituted arenes via streamlined one-pot process.

Язык: Английский

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Asymmetric multi-component trifunctionalization reactions with α-Halo Rh-carbenes

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 7, 2025

Multi-component multi-functionalization reactions involving active intermediates are powerful tools for rapidly generating a wide array of compounds. Metal carbynoids, with their distinct reactivity, hold great promise developing synthetic methodologies. However, application in catalytic transfer has been hindered by the limited availability suitable precursors. In this study, we investigate potential α-halo Rh-carbenes, leveraging concept metal carbynoids reactions. Through chiral phosphoric acid-catalyzed asymmetric trifunctionalization, have developed method synthesizing variety α-cyclic ketal β-amino esters high yields and excellent enantioselectivity. Our extensive experimental computational studies reveal that Rh-carbenes exhibit carbynoid properties, which facilitate transformation into functionalized Fischer-type through decomposition C-halo bond.

Язык: Английский

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