Visible Light-Induced Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1543 - 1625

Published: Oct. 8, 2021

In recent years, visible light-induced transition metal catalysis has emerged as a new paradigm in organic photocatalysis, which led to the discovery of unprecedented transformations well improvement known reactions. this subfield complex serves double duty by harvesting photon energy and then enabling bond forming/breaking events mostly via single catalytic cycle, thus contrasting established dual photocatalysis an exogenous photosensitizer is employed. addition, approach often synergistically combines catalyst–substrate interaction with photoinduced process, feature that uncommon conventional photoredox chemistry. This Review describes early development advances emerging field.

Language: Английский

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Transition Metal-Catalyzed Organic Reactions under Visible Light: Recent Developments and Future Perspectives

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(16), P. 9170 - 9196

Published: July 20, 2020

The development of transition metal (TM) catalysis for organic synthesis under visible light without recourse to typical photoredox catalysts has become a rapidly growing area research and been actively explored in the past several years. Distinct from extensively developed catalysis, which photocatalyst generally does not directly participate bond-forming process, photocatalyst/TM synergistic absorbs photon energy transfers TM catalyst through redox or transfer this Review focuses on summarizing recent developments photocatalytic reactions that use complexes both absorb catalytic bond formation involving covalently bonded intermediate. contents are categorized by used (Pd, Cu, Co, Ni, Mn, Au, Rh, Fe, Ru), with descending sequence according number examples reported each metal, provide an overview April 2020. Future perspectives personal opinions regarding expanding field also discussed.

Language: Английский

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Transition Metal (Ni, Cu, Pd)-Catalyzed Alkene Dicarbofunctionalization Reactions

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(17), P. 3415 - 3437

Published: Aug. 12, 2021

ConspectusRecently, alkene dicarbofunctionalization, i.e., the powerful organic synthesis method of difunctionalization with two carbon sources, emerged as a formidable reaction immense promise to synthesize complex molecules expeditiously from simple chemicals. This is generally achieved transition metals (TMs) through interception by sources an alkylmetal [β-H–C(sp3)–[M]] species, key intermediate prone undergo rapid β-H elimination. Related prior reports, since Paolo Chiusoli and Catellani's work in 1982 [ Tetrahedron Lett. 1982, 23, 4517], have used bicyclic disubstituted terminal alkenes, wherein elimination avoided geometric restriction or complete lack β-H's. With reasoning that β-H–C(sp3)–[M] intermediates could be rendered amenable use first row late TMs formation coordination-assisted transient metallacycles, these strategies were implemented address problem dicarbofunctionalization reactions.Because catalyze C(sp3)–C(sp3) coupling, Cu Ni anticipated impart sufficient stability intermediates, generated catalytically upon carbometalation, for their subsequent electrophiles/nucleophiles three-component reactions. Additionally, such innate property enable coupling partners entropically driven cyclization/coupling The cyclometalation concept stabilize intractable was hypothesized when reactions performed. idea curtail founded Whitesides's J. Am. Chem. Soc. 1976, 98, 6521] observation metallacycles much slower than acyclic alkylmetals.In this Account, examples demonstrate catalysts alkenylzinc reagents, alkyl halides, aryl halides afford carbo- heterocycles. In addition, forming nickellacycles enabled regioselective performance various alkenyl compounds. situ [M]-H alkenes after induced unprecedented metallacycle contraction process, which six-membered metal-containing rings shrank five-membered cycles, allowing creation new carbon–carbon bonds at allylic (1,3) positions. Applications are discussed.

Language: Английский

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Three-Component, Interrupted Radical Heck/Allylic Substitution Cascade Involving Unactivated Alkyl Bromides

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(22), P. 10173 - 10183

Published: May 7, 2020

Developing efficient and selective strategies to approach complex architectures containing (multi)stereogenic centers has been a long-standing synthetic challenge in both academia industry. Catalytic cascade reactions represent powerful means of rapidly leveraging molecular complexity from simple feedstocks. Unfortunately, carrying out Heck-type involving unactivated (tertiary) alkyl halides remains an unmet owing unavoidable β-hydride elimination. Herein, we show that modular, practical, general palladium-catalyzed, radical three-component coupling can indeed overcome the aforementioned limitations through interrupted Heck/allylic substitution sequence mediated by visible light. Selective 1,4-difunctionalization 1,3-dienes, such as butadiene, achieved employing different commercially available nitrogen-, oxygen-, sulfur-, or carbon-based nucleophiles bromides (>130 examples, mostly >95:5 E/Z, >20:1 rr). Sequential C(sp3)–C(sp3) C–X (N, O, S) bonds have constructed efficiently with broad scope high functional group tolerance. The flexibility versatility strategy illustrated gram-scale reaction streamlined syntheses ether, sulfone, tertiary amine products, some which would be difficult access via currently established methods.

Language: Английский

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Nickel‐Catalyzed Asymmetric Reductive Arylalkylation of Unactivated Alkenes

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(20), P. 6722 - 6726

Published: March 20, 2019

Abstract Reported is an asymmetric reductive dicarbofunctionalization of unactivated alkenes. Under the catalysis a Ni/BOX system, various aryl bromides, incorporating pendant olefinic unit, were successfully reacted with array primary alkyl bromides in presence Zn as reductant, furnishing series benzene‐fused cyclic compounds bearing quaternary stereocenter high enantioselectivities. Notably, this reaction avoids use pregenerated organometallics and demonstrates tolerance sensitive functionalities. The preliminary mechanistic investigations reveal that Ni‐catalyzed proceeds cascade consisting migratory insertion cross‐coupling nickel(I)‐mediated intramolecular 5‐ exo cyclization enantiodetermining step.

Language: Английский

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Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(22), P. 9932 - 9937

Published: May 14, 2020

A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugated dienes has been developed. This mild modular approach, which does not require employment exogeneous photosensitizers and external oxidants, allows for efficient highly regio- stereoselective synthesis a broad range allylic amines from readily available 1,3-dienes, alkyl iodides, amines. Employment O- C-nucleophiles toward oxyalkylation dialkylation products was also demonstrated. putative π-allyl palladium radical-polar crossover path is proposed as key event in this three-component coupling process. The utility protocol highlighted by its application derivatization several amine-containing drugs.

Language: Английский

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Palladium Hydride-Enabled Hydroalkenylation of Strained Molecules

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(45), P. 20875 - 20883

Published: Oct. 31, 2022

We report the first palladium hydride enabled hydroalkenylation of strained molecules. This new mild protocol proceeds via a regio- and chemoselective hydropalladation step, followed by photoinduced radical alkyl Heck reaction. methodology represents reactivity mode for molecules opens avenues catalysis. The reaction is compatible with wide range functional groups can be applied to complex structures, delivering diverse array highly valuable modifiable alkenylated cyclobutanes cyclopropanes. A hydroalkenylation/diastereoselective rearrangement cascade toward cyclopentene scaffold has also been demonstrated.

Language: Английский

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Recent Advances in Visible Light Induced Palladium Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(9)

Published: Nov. 14, 2023

Visible light-induced Pd catalysis has emerged as a promising subfield of photocatalysis. The hybrid nature radical species enabled wide array radical-based transformations otherwise challenging or unknown via conventional chemistry. In parallel to the ongoing pursuit alternative, readily available precursors, notable discoveries have demonstrated that photoexcitation can alter not only oxidative addition but also other elementary steps. This Minireview highlights recent progress in this area.

Language: Английский

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Photoinduced, Palladium-Catalyzed Enantioselective 1,2-Alkylsulfonylation of 1,3-Dienes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3725 - 3732

Published: Feb. 21, 2024

The chiral allylic sulfonylated group is a unique structural motif embedded in range of natural products and pharmaceuticals. Notably, the synthesis structurally diverse derivatives via alkylsulfonylation 1,3-dienes remains underexplored because its inherent challenges stereocontrol regioselectivity. Herein, photoinduced, palladium-catalyzed enantioselective 1,2-alkylsulfonylation conjugated described. A wide variety alkyl bromides, 1,3-dienes, sodium sulfinates could be facilely coupled to generate value-added with high enantioselectivity. Finally, utility this difunctionalization protocol was demonstrated pharmaceutical analogue synthesis.

Language: Английский

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Palladium-Catalyzed Dual Ligand-Enabled Alkylation of Silyl Enol Ether and Enamide under Irradiation: Scope, Mechanism, and Theoretical Elucidation of Hybrid Alkyl Pd(I)-Radical Species

ACS Catalysis, Journal Year: 2019, Volume and Issue: 10(2), P. 1334 - 1343

Published: Dec. 19, 2019

We report herein that a palladium catalyst in combination with dual phosphine ligand system catalyzes alkylation of silyl enol ether and enamide broad scope tertiary, secondary, primary alkyl bromides under mild irradiation conditions by blue light-emitting diodes. The reactions effectively deliver α-alkylated ketones N-acyl ketimines, it is difficult to prepare the latter other methods stereoselective manner. ketimine products can be further subjected chiral phosphoric acid-catalyzed asymmetric reduction Hantzsch ester N-acyl-protected α-arylated aliphatic amines high enantioselectivity up 99% ee, thus providing method for facile synthesis amines, which are importance medicinal chemistry research. N-acetyl product also reacted smoothly various types Grignard reagents afford sterically bulky α-tertiary yields. Theoretical studies experimental investigation provide understanding reaction mechanism respect effect catalytic cycle. suggested proceed via hybrid Pd(I)-radical species generated inner-sphere electron transfer phosphine-coordinated Pd(0) bromide. This intriguing elucidated theoretical calculation triplet coordinated three atoms distorted tetrahedral geometry, spin prohibition rather than metal-to-ligand charge contributes kinetic stability impede recombination generate Pd(II) intermediate.

Language: Английский

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