Acceleration Mechanisms of C–H Bond Functionalization Catalyzed by Electron-Deficient CpRh(III) Complexes

ACS Catalysis, Год журнала: 2021, Номер 11(21), С. 13591 - 13602

Опубликована: Окт. 26, 2021

A rhodium(III) complex bearing a 1,3-bis(ethoxycarbonyl)-substituted or an unsubstituted cyclopentadienyl ligand (CpE Cp) significantly accelerates variety of oxidative C–H bond functionalization reactions. However, the driving force acceleration compared with conventionally used Cp*Rh(III) has not been elucidated. Herein, we performed density functional theory (DFT) calculations rhodium(III)-catalyzed olefination and annulation reactions using Cp*, Cp, CpE ligands, which revealed that CpERh(III) stabilizes transition states only activation step but also rate-determining reductive elimination insertion steps by strong orbital interactions. For sterically demanding substrates, less hindered CpRh(III) can stabilize more than complex. Moreover, whole reaction pathways were calculated to elucidate mechanism selectivity [4 + 2] [2 2 under cationic neutral conditions, respectively.

Язык: Английский

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Metal-Free Boron-Mediated ortho-C–H Hydroxylation of N-Benzyl-3,4,5-tribromopyrazoles

Organic Letters, Год журнала: 2022, Номер 24(19), С. 3570 - 3575

Опубликована: Май 5, 2022

A novel route has been reported for C-H hydroxylation of benzyl compounds directed by a 3,4,5-tribromopyrazole auxiliary via boronation/oxidation using BBr3 and NaBO3·4H2O. The strategy exhibits outstanding site selectivity affords the corresponding phenols in moderate to excellent yields under metal-free conditions. Besides, this protocol can be achieved one pot, which is highly promising as practical method use multistep organic synthetic process.

Язык: Английский

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Iron/Photosensitizer Hybrid System Enables the Synthesis of Polyaryl-Substituted Azafluoranthenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(40), С. 18450 - 18458

Опубликована: Сен. 27, 2022

Photosensitization of organometallics is a privileged strategy that enables challenging transformations in transition-metal catalysis. However, the usefulness such photocatalyst-induced energy transfer has remained opaque iron-catalyzed reactions despite intriguing prospects iron catalysis synthetic chemistry. Herein, we demonstrate use iron/photosensitizer-cocatalyzed cycloaddition to synthesize polyarylpyridines and azafluoranthenes, which have been scarcely accessible using established protocols. Mechanistic studies indicate triplet from photocatalyst ferracyclic intermediate facilitates thermally demanding nitrile insertion accounts for distinct reactivity hybrid system. This study thus provides first demonstration role photosensitization overcoming limitations

Язык: Английский

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Merging Visible Light Photocatalysis and P(III)‐Directed C−H Activation by a Single Catalyst: Modular Assembly of P‐Alkyne Hybrid Ligands

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(47)

Опубликована: Окт. 10, 2023

Metal-catalyzed C-H activation strategies provide an efficient approach for synthesis by minimizing atom, step, and redox economy. Developing milder, greener, more effective protocols these is always highly desirable to the scientific community. In this study, utilization of a single rhodium complex enabled visible-light-induced late-stage biaryl-type phosphines with alkynyl bromides, employing inherent phosphorus atoms as directing groups. This chemistry combines P(III)-directed visible light photocatalysis, under exogenous photosensitizer-free conditions, offering unique platform ligand design preparation. Furthermore, study also explores asymmetric catalysis coordination resulting P-alkyne hybrid ligands specific transition metals. Experimental results density functional theory calculations demonstrate mechanistic intricacies transformation.

Язык: Английский

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An unusual reaction in nitromethane solution: use of the Cp*Rh moiety to form Prussian blue analogues

Inorganic Chemistry Frontiers, Год журнала: 2024, Номер 11(9), С. 2590 - 2597

Опубликована: Янв. 1, 2024

The direct decomposition of nitromethane into nitrile compounds is a significant challenge due to the occurrence severe side-reactions.

Язык: Английский

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Photochemical C–H Borylation in Organic Synthesis

ACS Catalysis, Год журнала: 2025, Номер 15(3), С. 1753 - 1770

Опубликована: Янв. 16, 2025

Although C–H bond functionalization has been extensively studied since its discovery in 1955, the borylation of organic compounds by activating bonds only became popular valuable Hartwig 1995 who considered a wider application these transformations synthetic chemistry. For borylation, catalytic activation this generally low-reactivity can be performed many ways. Among approaches reported are use and stoichiometric reagents, thermal activation, photochemical suitable substrates. Iridium-, ruthenium-, rhodium-based protocols using have played crucial role toward establishment area. Photochemical though, scarcely explored despite fact that it represents comparably environmentally benign protocol light as renewable energy source. In literature survey, we highlight recent developments from initial inception up to latest advancements.

Язык: Английский

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Visible-light-induced C2-selective trifluoromethylation of indoles catalyzed by copper-containing covalent organic frameworks

Journal of Catalysis, Год журнала: 2025, Номер unknown, С. 116077 - 116077

Опубликована: Март 1, 2025

Язык: Английский

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Photoinduced Ruthenium-Catalyzed meta-C–H Glycosylation

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 10542 - 10549

Опубликована: Июнь 5, 2025

Язык: Английский

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Unlocking C–H Functionalization at Room Temperature via a Light-Mediated Protodemetalation Reaction

ACS Catalysis, Год журнала: 2022, Номер 12(14), С. 8229 - 8236

Опубликована: Июнь 26, 2022

Herein, we report on the photocatalytic ortho-alkylation reaction of 2-phenyl pyridines with N-protected maleimides using [Cp*RhCl2]2 as a catalyst and propionic acid an additive at room temperature. Experimental theoretical studies suggest mechanism that consists dark light reaction: while cyclometalation migratory insertion can proceed temperature in dark, photochemical excitation intermediates is required to facilitate decomplexation directing group allow ligand exchange acid. This enables facile protodemetalation regenerate give product. We studied this broad substrate scope, including different groups N-substituted yield succinimides high (49 examples, up 96% yield).

Язык: Английский

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Photocatalytic Generations of Secondary and Tertiary Silyl Radicals from Silylboranes Using an Alkoxide Cocatalyst

The Journal of Organic Chemistry, Год журнала: 2022, Номер 88(15), С. 10371 - 10380

Опубликована: Окт. 10, 2022

Silyl radicals are valuable species to prepare diverse organosilicon compounds. However, unlike stable tertiary silyl radicals, the use of secondary has been problematic in silylation reactions due their instability. Here, we present photocatalytic situ generations both and by one-electron oxidation ate complexes, formed from silylboranes an alkoxide cocatalyst, achieving highly efficient hydrosilylation deuterosilylation electron-rich alkenes dienes as well electron-deficient alkenes. The theoretical studies show that anionic borate complexes activated with have lower potentials than neutral allowing formation radicals. calculated reaction pathways reveal conditions using conjugate acid-base pair NaOEt (cocatalyst) EtOH (solvent) key expanding scope

Язык: Английский

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