Merging excited-state copper catalysis and triplet nitro(hetero)arenes for direct synthesis of 2-aminophenol derivatives

Chem, Год журнала: 2023, Номер 10(2), С. 686 - 697

Опубликована: Дек. 11, 2023

Язык: Английский

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Atroposelective P^III/P^V=O Redox Catalysis for the Isoquinoline‐Forming Staudinger–aza‐Wittig Reaction

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(39)

Опубликована: Июль 24, 2023

Herein, we describe the feasibility of atroposelective PIII /PV =O redox organocatalysis by Staudinger-aza-Wittig reaction. The formation isoquinoline heterocycles thereby enables synthesis a broad range valuable atropisomers under mild conditions with enantioselectivities up to 98 : 2 e.r. Readily prepared azido cinnamate substrates convert in high yield stereocontrol chiral phosphine catalyst, which is regenerated using silane reductant Brønsted acid co-catalysis. reaction provides access diversified aryl isoquinolines, as well benzoisoquinoline and naphthyridine atropisomers. products are expeditiously transformed into N-oxides, naphthol triaryl variants prevalent catalysts ligands. With dinitrogen release aromatization ideal driving forces, it anticipated that multitude aromatic precise control over their configuration.

Язык: Английский

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Mechanistic Details of Asymmetric Bromocyclization with BINAP Monoxide: Identification of Chiral Proton-Bridged Bisphosphine Oxide Complex and Its Application to Parallel Kinetic Resolution

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(9), С. 3913 - 3924

Опубликована: Фев. 28, 2022

The mechanism of our previously reported catalytic asymmetric bromocyclization reactions using 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) monoxide was examined in detail by the means control experiments, NMR studies, X-ray structure analysis, and CryoSpray electrospray ionization mass spectrometry (ESI-MS) analysis. chiral BINAP transformed to a key catalyst precursor, proton-bridged bisphosphine oxide complex (POHOP·Br), presence N-bromosuccinimide (NBS) contaminating water. thus-formed POHOP further reacts with NBS afford dioxide molecular bromine (Br2) simultaneously equimolar amounts. While resulting Br2 is activated form more reactive brominating reagent (Br2─NBS), serves as bifunctional catalyst, acting both Lewis base that Br2─NBS agent (P═O+─Br) also Brønsted for activation substrate. By taking advantage this novel concerted Lewis/Brønsted catalysis dioxide, we achieved first regio- chemodivergent parallel kinetic resolutions (PKRs) racemic unsymmetrical bisallylic amides via bromocyclization.

Язык: Английский

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Organophosphorus catalytic reaction based on reduction of phosphine oxide

Green Synthesis and Catalysis, Год журнала: 2022, Номер 4(2), С. 135 - 149

Опубликована: Окт. 27, 2022

The special electronic configuration of phosphorus atoms endows organophosphorus reagents with unique chemical properties, which enable them to be used catalyze various organic reactions, such as the Wittig reaction, Staudinger Appel reaction and Mitsunobu reaction. However, catalytic process will accompanied by generation large amounts phosphine oxide waste, resulting in reduction atom utilization it is difficult separate product. Therefore, essential explore a greener more sustainable synthesis route based on cycle model. This paper summarizes recycling or without reducing agents reviews related developments recent decades: from addition stoichiometric strong agents, design ring phosphines specific structures, development new energy inputs (electrochemistry), series compounds activate P(V)O double bond, driving through transformation. review also points out potential this field future, promote its progress direction.

Язык: Английский

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Mechanistic Studies on the Bismuth‐Catalyzed Transfer Hydrogenation of Azoarenes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(49)

Опубликована: Сен. 28, 2023

Organobismuth-catalyzed transfer hydrogenation has recently been disclosed as an example of low-valent Bi redox catalysis. However, its mechanistic details have remained speculative. Herein, we report experimental and computational studies that provide insights into a Bi-catalyzed azoarenes using p-trifluoromethylphenol (4) pinacolborane (5) hydrogen sources. A kinetic analysis elucidated the rate orders in all components catalytic reaction determined 1 (2,6-bis[N-(tert-butyl)iminomethyl]phenylbismuth) is resting state. In azobenzene 4, equilibrium between ⋅ [OAr]2 (Ar=p-CF3 -C6 H4 ) observed, thermodynamic parameters are established through variable-temperature NMR studies. Additionally, pKa -gated reactivity validating proton-coupled nature transformation. The ensuing crystallographically characterized, shown to be rapidly reduced presence 5. DFT calculations indicate rate-limiting transition state which initial N-H bond formed via concerted proton upon nucleophilic addition hydrogen-bonded adduct 4. These guided discovery second-generation catalyst, lower energy, leading at catalyst loadings cryogenic temperature.

Язык: Английский

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Organophosphorus-Catalyzed Direct Dehydroxylative Thioetherification of Alcohols with Hypervalent Organosulfur Compounds

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(2), С. 1083 - 1090

Опубликована: Янв. 4, 2024

A metal-free and thiol-free organophosphorus-catalyzed method for forming thioethers was disclosed, driven by PIII/PV═O redox cycling. In this work, one-step dehydroxylative thioetherification of alcohols fulfilled with various hypervalent organosulfur compounds. This established strategy features an excellent functional group tolerance broad substrate scope, especially inactivated alcohols. The scale-up reaction further transformation the product were also successful. Additionally, offers a protecting-group-free step-efficient approach synthesizing peroxisome proliferator-activated receptor agonists which exhibited promising potential treating osteoporosis in mammals.

Язык: Английский

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Bisgermylene-Stabilized Stannylone: Catalytic Reduction of Nitrous Oxide and Nitro Compounds via Element-Ligand Cooperativity

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(26), С. 17817 - 17826

Опубликована: Май 23, 2024

This study describes the synthesis, structural characterization, and catalytic application of a bis(germylene)-stabilized stannylone (

Язык: Английский

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The Outstanding Ambiphilicity of Trialkylstibines among Trialkylpnictines: Power for Stepwise Deoxygenation and N–N Coupling of Nitroarenes

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 12, 2025

The ongoing discovery of highly reactive ambiphilic main-group species has significantly advanced the development chemistry, particularly in realms small molecule activation and catalysis. Theoretically, compounds featuring smaller HOMO–LUMO gaps gain stronger ambiphilicity higher reactivity. In this work, we fundamentally demonstrate that Me3Sb holds smallest gap among trimethylpnictines, indicating its outstanding ambiphilicity. Correspondingly, superior reactivity toward deoxygenation electron-deficient nitroarenes been unambiguously revealed through control experiments. Furthermore, unprecedented SbIII/SbVO cycling between trialkylstibines their oxides established for catalytic transformation into azoxyarenes/azoarenes. This study opens a new chapter organoantimony derivatives fields redox

Язык: Английский

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Combined Computational and Experimental Study Reveals Complex Mechanistic Landscape of Brønsted Acid-Catalyzed Silane-Dependent P═O Reduction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(20), С. 13983 - 13999

Опубликована: Май 13, 2024

The reaction mechanism of Brønsted acid-catalyzed silane-dependent P═O reduction has been elucidated through combined computational and experimental methods. Due to its remarkable chemo- stereoselective nature, the acid/silane system widely employed in organophosphine-catalyzed transformations involving P(V)/P(III) redox cycle. However, full mechanistic profile this type yet be clearly established date. Supported by both DFT studies, our research reveals that likely proceeds mechanisms other than accepted "dual activation mode silyl ester" or "acid-mediated direct activation" mechanism. We propose although may vary with substitution patterns silane species, acid generally activates rather group transition structures. proposed differs significantly from associated traditional C═O reduction. uniqueness originates dominant Si/O═P orbital interactions structures P/H–Si interactions. comprehensive landscape provided us will serve as a guidance for rational design development more efficient systems well novel reactions

Язык: Английский

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Ligand‐Enabled Disproportionation of 1,2‐Diphenylhydrazine at a P^V‐Center**

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(35)

Опубликована: Июнь 17, 2022

We present herein the synthesis of a nearly square-pyramidal chlorophosphorane supported by tetradentate bis(amidophenolate) ligand, N,N'-bis(3,5-di-tert-butyl-2-phenoxy)-1,2-phenylenediamide. After chloride abstraction resulting phosphonium cation efficiently promotes disproportionation 1,2-diphenylhydrazine to aniline and azobenzene. Mechanistic studies, spectroscopic analyses theoretical calculations suggest that this unprecedented reactivity mode for P

Язык: Английский

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