Mechanisms of Photoredox Catalysis Featuring Nickel–Bipyridine Complexes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(11), P. 9055 - 9076

Published: May 29, 2024

Metallaphotoredox catalysis can unlock useful pathways for transforming organic reactants into desirable products, largely due to the conversion of photon energy chemical potential drive redox and bond transformation processes. Despite importance these processes cross-coupling reactions other transformations, their mechanistic details are only superficially understood. In this review, we have provided a detailed summary various photoredox mechanisms that been proposed date Ni-bipyridine (bpy) complexes, focusing separately on photosensitized direct excitation reaction By highlighting multiple key findings, depict how mechanisms, which ultimately define substrate scope, themselves defined by ground- excited-state geometric electronic structures Ni-based intermediates. We further identify knowledge gaps motivate future studies development synergistic research approaches spanning physical, organic, inorganic chemistry communities.

Language: Английский

---

Ni‐Catalyzed Photochemical C−N Coupling of Amides with (Hetero)aryl Chlorides

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(37)

Published: April 17, 2023

This paper reports a photochemical C-N coupling of abundant, but less reactive aryl chlorides, with structurally diverse primary and secondary amides by Ni-mediated without an external photocatalyst. Under the irradiation light (390-395 nm) soluble organic amine as base, reaction allows for successful transformation (hetero)aryl chlorides to wide range N-aryl amides. More than 60 examples are shown, demonstrating feasibility applicability this protocol in synthesis. Mechanic studies indicate that amidation proceeds via Ni(I)-Ni(III) catalytic cycle.

Language: Английский

---

Dual role of nitroarenes as electrophiles and arylamine surrogates in Buchwald–Hartwig-type coupling for C–N bond construction

Chemical Science, Journal Year: 2024, Volume and Issue: 15(10), P. 3552 - 3561

Published: Jan. 1, 2024

A reductive and denitrative amination of nitroarenes has been developed, allowing the highly selective synthesis various di- triarylamines. The protocol employed synthetically upstream as both electrophiles amine sources.

Language: Английский

---

Werner Salt as Nickel and Ammonia Source for Photochemical Synthesis of Primary Aryl Amines

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(6)

Published: Nov. 2, 2023

Cheap, stable and easy-to-handle Werner ammine salts have been known for more than a century; but they rarely used in organic synthesis. Herein, we report that the hexammine complex [Ni(NH

Language: Английский

---

Excited-State Nickel-Catalyzed Amination of Aryl Bromides: Synthesis of Diphenylamines and Primary Anilines

Organic Letters, Journal Year: 2024, Volume and Issue: 26(8), P. 1657 - 1661

Published: Feb. 21, 2024

Excited-state nickel-catalyzed C–N cross-coupling of aryl bromides with sodium azide enables the synthesis diarylamines and primary anilines under mild reaction conditions. The oxidative addition electron-rich low-valent Ni photochemical conditions is endothermic. Herein, we demonstrate a light-mediated electronically rich that yields diarylamines, while electron-deficient gives access to at room temperature.

Language: Английский

---

Leveraging the Redox Promiscuity of Nickel To Catalyze C–N Coupling Reactions

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 17, 2024

This perspective details advances made in the field of Ni-catalyzed C–N bond formation. The use this Earth abundant metal to decorate amines, amides, lactams, and heterocycles enables direct access a variety biologically active industrially relevant compounds sustainable manner. Herein, different strategies that leverage propensity Ni facilitate both one- two-electron processes will be surveyed. first part Perspective focuses on couplings at room temperature by accessing oxidized Ni(III) intermediates. In context, photochemical, electrochemical, chemically mediated analyzed. A special emphasis has been put providing comprehensive explanation mechanistic avenues have proposed these chemistries; either Ni(I/III) self-sustained cycles or Ni(0/II/III) photochemically pathways. second ligand designs also enable reactivity via Ni(0/II) mechanism. Finally, we discuss our thoughts possible future directions field.

Language: Английский

---

Photoredox/nickel dual-catalysis-enabled synthesis of N-heterocycles from alkyl chlorides and alkenes

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 553, P. 113806 - 113806

Published: Jan. 1, 2024

Language: Английский

---

Light-Promoted Efficient Generation of Fe(I) to Initiate Amination

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 4968 - 4974

Published: March 18, 2024

Iron-catalyzed cross-coupling reactions are difficult to achieve because they usually require a highly reactive, low-valent iron catalyst undergo the oxidative addition process. Here, we report method for light-promoted iron-catalyzed C–N coupling between aryl bromides and amines in presence of catalytic amount bipyridine ligand under irradiation at 390–395 nm. This method, which does not external photosensitizers, features broad substrate scope (70 examples) good functional group tolerance, providing platform development organic synthesis. Mechanistic studies indicate that an base light crucial generation Fe(I) species reaction involves Fe(I)/Fe(III) cycle.

Language: Английский

---

Photoexcitation of Distinct Divalent Palladium Complexes in Cross‐Coupling Amination Under Air

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(3)

Published: Nov. 13, 2023

Abstract The development of metal complexes that function as both photocatalyst and cross‐coupling catalyst remains a challenging research topic. So far, progress has been shown in palladium(0) excited‐state transition catalysis for the construction carbon‐carbon bonds where oxidative addition alkyl/aryl halides to zero‐valent palladium (Pd 0 ) is achievable at room temperature. In contrast, analogous process with divalent II uphill endothermic. For first time, we report can act light‐absorbing species undergoes double excitation realize carbon‐nitrogen (C−N) cross‐couplings under air. Differently substituted aryl be applied mild, selective amination using acetate Density functional theory studies supported by mechanistic investigations provide insight into reaction mechanism.

Language: Английский

---

Photoexcited Ni^II–Aryl Complex-Mediated Giese Reaction of Aryl Bromides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(22), P. 4056 - 4060

Published: May 31, 2023

A Giese reaction of aryl bromides with electron-deficient alkenes was developed, enabled by a dual catalyst system containing NiII complex and IrIII photocatalyst. This protocol could accommodate variety alkenes, delivering the conjugate adducts in up to 97% yield. The utilization photoexcited (dtbbpy)NiII(aryl)Br intermediate as an radical source allows this novel transformation halides, thus expanding chemical space excited nickel catalysis.

Language: Английский

---