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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Excited-State Palladium-Catalyzed Radical Migratory Mizoroki–Heck Reaction Enables C2-Alkenylation of Carbohydrates

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(8), P. 3353 - 3359

Published: Feb. 21, 2022

Excited-state palladium catalysis has emerged as a promising strategy for developing novel and valuable reactions. Herein, we report the first excited-state Pd-catalyzed 1,2-radical migratory Mizoroki–Heck reaction that enables C2-alkenylation of carbohydrates using readily available 1-bromosugars alkenes. The tolerates wide variety functional groups complex molecular architectures, including derivatives natural products marketed drugs. Preliminary mechanistic studies DFT calculations suggest involvement visible-light-induced photoexcitation Pd species, 1,2-spin-centered-shift (SCS) process, Heck-type cross-coupling reaction. expands reactivity profile provides streamlined protocol preparation C2-alkenylated carbohydrate mimetics to aid discovery development new therapeutics, agrochemicals, materials.

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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Catalysis in the Excited State: Bringing Innate Transition Metal Photochemistry into Play

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 4665 - 4680

Published: March 5, 2025

Transition metal catalysis is an indispensable tool for organic synthesis that has been harnessed, modulated, and perfected many decades by careful selection of centers ligands, giving rise to synthetic methods with unparalleled efficiency chemoselectivity. Recent developments have demonstrated how light irradiation can also be recruited as a powerful dramatically alter the outcome catalytic reactions, providing access innovative pathways remarkable potential. In this context, adoption photochemical conditions mainstream strategy drive reactions unveiled exciting opportunities exploit rich excited-state framework transition metals applications. This Perspective examines advances in application complexes standalone photocatalysts, exploiting innate reactivity their excited states beyond common use photoredox catalysts. An account relevant examples dissected provide discussion on electronic reorganization, orbitals involved, associated different types states. analysis aims practitioners fundamental principles guiding strategies understand, design, apply light-activation homogeneous synthesis.

Language: Английский

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Unactivated Alkyl Chloride Reactivity in Excited-State Palladium Catalysis

Organic Letters, Journal Year: 2021, Volume and Issue: 23(17), P. 6905 - 6910

Published: Aug. 25, 2021

Excited-state palladium catalysis is an efficient process for the alkylation of diverse organic compounds via generation alkyl radicals from bromides and iodides. However, more stable chlorides remains challenging. Herein, we demonstrate excited-state palladium-catalyzed synthesis oxindoles isoquinolinediones alkylation/annulation reaction by overcoming inherent limitations associated with unactivated C(sp3)–Cl bond activation at room temperature.

Language: Английский

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Photoinduced Palladium-Catalyzed 1,2-Difunctionalization of Electron-Rich Olefins via a Reductive Radical-Polar Crossover Reaction

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(9), P. 6445 - 6451

Published: April 25, 2023

Palladium-catalyzed cross-coupling reactions belong to the most important transformations for construction of C–C or C-heteroatom bonds. More recently, photochemical activation palladium complexes emerged as a key strategy leverage catalysis at room temperature beyond scope conventional chemistry. Herein, we report on photoinduced palladium-catalyzed 1,2-difunctionalization reaction electron-rich olefins. Mechanistic experiments and computational studies reveal that this proceeds via addition an alkyl radical, followed by oxidation radical intermediate access carbocation intermediates, which are inaccessible classic thermal conditions. The can then be applied variety secondary C–N bond-forming reactions. This now allows general approach toward densely functionalized unsymmetric 1,1-bis(heterocyclyl)alkanes.

Language: Английский

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Catalytic Asymmetric Cascade Dearomatization of Indoles via a Photoinduced Pd‐Catalyzed 1,2‐Bisfunctionalization of Butadienes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(26)

Published: April 20, 2024

Photoinduced Pd-catalyzed bisfunctionalization of butadienes with a readily available organic halide and nucleophile represents an emerging attractive method to assemble versatile alkenes bearing various functional groups at the allylic position. However, enantiocontrol and/or diastereocontrol in C-C or C-X bond-formation step have not been solved due open-shell process. Herein, we present cascade asymmetric dearomatization reaction indoles via photoexcited 1,2-biscarbonfunctionalization 1,3-butadienes, wherein control on both electrophile part is achieved for first time photoinduced butadienes. This delivers structurally novel chiral spiroindolenines two contiguous stereogenic centers high diastereomeric ratios (up >20 : 1 dr) good excellent enantiomeric 97 3 er). Experimental computational studies mechanism confirmed radical pathway involving excited-state palladium catalysis. The alignment non-covalent interactions between substrate catalyst were found be essential stereocontrol.

Language: Английский

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Photoinduced Desaturation of Amides by Palladium Catalysis

Organic Letters, Journal Year: 2022, Volume and Issue: 24(35), P. 6460 - 6465

Published: Aug. 30, 2022

A photoinduced palladium-catalyzed desaturation method that is suitable for converting the linear amides to their α,β-unsaturated counterparts reported. The reaction does not require strong base/acid or sulfur/selenium and oxidant reagents can be carried out at room temperature through a simple one-step operation. protocol exhibits great scalability functional group tolerance. mechanism has been investigated deuterium labeling experiments, radical clock, capture, kinetic studies. Mechanistic studies suggested pathway involving aryl/alkyl Pd-radical intermediates.

Language: Английский

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Direct Alkylation of Glycine Derivatives via Photoinduced Palladium Catalysis, Utilizing Intermolecular Hydrogen Atom Transfer Mediated by Alkyl Radicals

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(24), P. 15652 - 15662

Published: Nov. 21, 2023

Unveiling the alkyl/Pd hybrid species is a unique sp3-C-centered radical for facilitating intermolecular hydrogen atom transfer (HAT) in development of direct alkylation glycine derivatives. This transformative reaction proceeds smoothly under simple and mild conditions, exhibiting impressive versatility terms substrate scope encompassing both derivatives alkyl bromides while showcasing remarkable tolerance toward diverse functional groups. To shed light on underlying mechanism, extensive investigations involving control experiments, deuterium labeling, clocking, kinetic studies have been conducted. The collected data consistently support pathway formation Pd(I)/alkyl followed by HAT elimination steps that lead to situ imine intermediates, ultimately culminating final stage through addition.

Language: Английский

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Cationic-palladium catalyzed regio- and stereoselective syn-1,2-dicarbofunctionalization of unsymmetrical internal alkynes

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: March 16, 2022

Abstract π-Extended tetrasubstituted olefins are widely found motifs in natural products, leading drugs, and agrochemicals. Thus, development of modular strategies for the synthesis complex all-carbon-substituted always draws attention. The difunctionalization unsymmetrical alkynes is an attractive approach but it has remained faced with regioselectivity issues. Here we report discovery a regio- stereoselective syn -1,2-dicarbofunctionalization internal alkynes. A cationic Pd-catalyzed three-component coupling aryl diazonium salts, boronic acids (or olefins) yne-acetates enables access to all-carbon substituted olefins. transformation features broad scope labile functional group tolerance, building chemical space structural diversity (94 molecules). value this synthetic method demonstrated by direct products drug candidates containing yne-acetates, enable highly structurally allyl acetate analogues biologically important compounds. Synthetic versatility carboxylate bearing also presented. reaction outcome attributed situ formation stabilized aryl-Pd species, which regulates regioselective aryl-palladation yne-acetates. Control experiments reveal synergy between protecting Pd-intermediate productivity; density theory (DFT) studies rationalize selectivity reaction.

Language: Английский

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