Ultrafast Photophysics of Ni(I)–Bipyridine Halide Complexes: Spanning the Marcus Normal and Inverted Regimes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 15506 - 15514

Published: May 22, 2024

Owing to their light-harvesting properties, nickel–bipyridine (bpy) complexes have found wide use in metallaphotoredox cross-coupling reactions. Key these transformations are Ni(I)–bpy halide intermediates that absorb a significant fraction of light at relevant reaction irradiation wavelengths. Herein, we report ultrafast transient absorption (TA) spectroscopy on library eight complexes, the first such characterization any Ni(I) species. The TA data reveal formation and decay Ni(I)-to-bpy metal-to-ligand charge transfer (MLCT) excited states (10–30 ps) whose relaxation dynamics well described by vibronic Marcus theory, spanning normal inverted regions as result simple changes bpy substituents. While lifetimes relatively long for MLCT first-row transition metal duration precludes excited-state bimolecular reactivity photoredox We also present one-step method generate an isolable, solid-state species, which decouples light-initiated from dark, thermal cycles catalysis.

Language: Английский

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Nickel-Catalyzed Amination of Aryl Halides: An Exogenous Ligand-Free Approach to Primary Arylamines Using Tmsn3

Published: Jan. 1, 2025

Language: Английский

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Latest Developments in Palladium and Nickel-Catalyzed Cross-Couplings for Aryl Chlorides: Suzuki-Miyaura and Buchwald-Hartwig Reactions

Synthesis, Journal Year: 2024, Volume and Issue: unknown

Published: June 13, 2024

Abstract Palladium- and nickel-catalyzed cross-couplings are powerful methods for constructing C–C C–N bonds, particularly through Suzuki–Miyaura Buchwald–Hartwig reactions. Although aryl iodides, bromides, triflates the most commonly used substrates, chlorides less frequently utilized due to their lower reactivity. However, they appealing because readily available inexpensive. This short review highlights recent developments on of chlorides, using both homogeneous heterogeneous catalysis with palladium nickel. 1 Introduction 2 Cross-Couplings 2.1 Homogeneous Palladium Catalysis 2.2 Heterogeneous 2.3 Nickel 2.4 3 Amination Reactions 3.1 3.2 3.3 3.4 4 Conclusion

Language: Английский

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Indole Nucleophile Triggers Mechanistic Divergence in Ni-Photoredox N–Arylation

Published: June 25, 2024

This study presents a Ni-photoredox method for indole N-arylation, broadening the range of substrates to include indoles with unprotected C3-positions and base-sensitive groups. Through detailed mechanistic inquiries, Ni(I/III) mechanism was uncovered, distinct from those commonly proposed Ni-catalyzed amine, thiol, alcohol arylation, as well Ni(0/II/III) cycle identified amide arylation under almost identical conditions. The key finding is formation Ni(I) intermediate bearing nucleophile ligand prior oxidative addition, which rare carbon-heteroatom coupling has profound impact on reaction kinetics scope. pre-coordination renders more electron-rich intermediate, broadens scope by enabling fast reactivity even challenging aryl bromide substrates. Thus, this work highlights often-overlooked influence X-type ligands Ni addition rates illustrates yet another divergence in C–heteroatom couplings.

Language: Английский

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Indole Nucleophile Triggers Mechanistic Divergence in Ni‐Photoredox N–Arylation

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: July 27, 2024

Abstract This study presents a Ni‐photoredox method for indole N ‐arylation, broadening the range of substrates to include indoles with unprotected C3‐positions and base‐sensitive groups. Through detailed mechanistic inquiries, Ni(I/III) mechanism was uncovered, distinct from those commonly proposed Ni‐catalyzed amine, thiol, alcohol arylation, as well Ni(0/II/III) cycle identified amide arylation under almost identical conditions. The key finding is formation Ni(I) intermediate bearing nucleophile ligand prior oxidative addition, which rare carbon‐heteroatom coupling has profound impact on reaction kinetics scope. pre‐coordination renders more electron‐rich intermediate, broadens scope by enabling fast reactivity even challenging aryl bromide substrates. Thus, this work highlights often‐overlooked influence X‐type ligands Ni addition rates illustrates yet another divergence in C‐heteroatom couplings.

Language: Английский

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Au,Ag,Cu Doped Niwo4 Hetergeneous with Exceptional Hydrogen Evolution Capability and Stability in Alkaline Media Under Large Current Density Exceeding 100 Ma Cm-2

Published: Jan. 1, 2024

Language: Английский

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Photocatalyzed amination of benzylic C(sp3)−H bonds via C−N coupling: Green synthesis and NMR analysis of N-benzylanilines

Journal of Molecular Structure, Journal Year: 2024, Volume and Issue: 1322, P. 140699 - 140699

Published: Nov. 9, 2024

Language: Английский

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