Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(11), P. 7214 - 7261

Published: May 16, 2024

In recent years, visible light-induced reactions of diazo compounds have attracted increasing attention in organic synthesis, leading to improvement existing reactions, as well the discovery unprecedented transformations. Thus, photochemical or photocatalytic generation both carbenes and radicals provide milder tools toward these key intermediates for many valuable However, vast majority transformations represent new reactivity modes compounds, which are achieved by decomposition photoredox catalysis. particular, use a redox-active photocatalysts opens avenue plethora radical reactions. The application methods led inaccessible classical associated with metal carbenes. most cases, act sources but can also serve acceptors. Importantly, described processes operate under mild, practical conditions. This Review describes this subfield compound chemistry, particularly focusing on advancements.

Language: Английский

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Visible-Light Photocatalyzed C3–H Alkylation of 2H-Indazoles/Indoles with Sulfoxonium Ylides via Diversified Mechanistic Pathways

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(2), P. 1193 - 1204

Published: Jan. 9, 2024

Herein, the C3–H alkylation of 2H-indazoles and indoles with sulfoxonium ylides is developed under visible-light photocatalysis. This protocol employs easily accessible reagents, a wide range 2H-indazoles, indoles, are suitable for this reaction to afford desired products benign conditions. Synergistic experimental computational studies suggest that involving photocatalysis could proceed via different mechanistic pathways. For C3-alkylation triplet energy transfer pathway proposed quenching excited photocatalyst. Subsequently, formed state undergo radical attack on C═S moiety ylides. After dissociation DMSO 1,2-H migration, final product be yielded. However, such not applicable indoles. Instead, converted C-centered in presence KH2PO4 photoredox The can C3-site thus lead

Language: Английский

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Synthesis of 2‐Quinolones based on Visible Light‐Catalyzed Annulation of Diazo compounds

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(8), P. 1827 - 1832

Published: Feb. 8, 2024

Abstract Herein, we report a photocatalytic method for the synthesis of 2‐quinolones under mild conditions by employing α‐diazo acetamide as substrates. The use Eosin Y photocatalyst allows an economical and environmentally benign synthetic method. process involves generation radicals from diazo compounds promoted visible‐light‐induced proton‐coupled electron transfer (PCET) mechanism. demonstrates broad substrate scope to provide various aryl‐ alkyl‐substituted 2‐quinolones. To support proposed mechanism, series mechanistic experiments were conducted.

Language: Английский

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Uncovering the On-Pathway Reaction Intermediates for Metal-Free Atom Transfer Radical Addition to Olefins through Photogenerated Phenalenyl Radical Anion

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3420 - 3433

Published: Feb. 16, 2024

Photoredox catalysis has emerged as a powerful approach for atom transfer radical addition (ATRA) while generating the desired intermediates that are otherwise difficult to access with traditional methods. However, photoredox ATRA organic photosensitizers is rare, giving an opportunity metal-free routes complex synthesis. Here, we demonstrate exquisite control of product selectivity reactions in situ generated carbenes form either cyclopropanated or corresponding hydroalkylation products phenalenyl-based photocatalyst through H/I-ATRA. A combination steady-state and time-resolved spectroscopic tools identified transient formation reactive phenalenyl anion drives photocatalysis. Kinetic isotope measurements along trapping methods mapped complete mechanistic cycle cyclopropanation well reaction styrene-based hydrocarbons. Our multicomponent H/I-ATRA methodology photogenerated shows high functional group tolerance encompassing biologically active molecules.

Language: Английский

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The Cascade Reaction Chemistry of Diazo Compounds with Intentionally Designed Alkene to Access Esterified Heterocycles

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Exploration of the cascade reactivity diazo compounds with alkenes is a challenging and largely unmet goal. Herein, we disclose light-mediated de novo synthesis esterified heterocycles under mild conditions. The reaction displays broad functional group tolerance, including wide variety alkenes, compounds, some bioactive molecules. Importantly, synthetic appeal was demonstrated for synthesizing indoleamine 2,3-dioxygenase inhibitor analogue, deethylated derivative natural product leucomidine C, anti-inflammatory agent AN669.

Language: Английский

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Spin States Matter─from Fundamentals toward Synthetic Methodology Development and Drug Discovery

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: 57(18), P. 2717 - 2727

Published: Sept. 2, 2024

ConspectusThe potent reactivity of carbenes and nitrenes has been traditionally harnessed by the employment a transition-metal catalyst in which metal carbene/nitrene intermediates can be controlled via judicious tuning catalyst. In recent years, progress made this research area unveiled novel strategies to directly access free or under visible-light-mediated conditions without necessity for stabilization intermediate. Such photochemical approaches present new opportunities leverage orthogonal reactions with classic metal-catalyzed transformations.In Account, we describe major contributions from our group over past years pushing boundaries light-mediated carbene nitrene transfer reactions. first section, development purely singlet chemistry toward methods that allow triplet will dissected. We how spin state reagents provides rich array synthetic build on fundamentals conservation. lay out different accessing (i.e., electronic stabilization, sensitization suitable photocatalysts, exploitation geometric features these intermediates), followed an analysis employed distinct chemistry.The second part focuses intermediates, whereby both photocatalytic are analyzed compared. initiate discussion iminoiodinanes as precursors presence photocatalyst two result fundamentally nitrogen-based intermediates. While radical anion is formed conditions, generated conditions. commence outline basic focus reaction substrates containing double bonds. Finally, latest developments advanced cycloaddition beyond aziridination examined, special emphasis relay enable Pauson-Khand-like (2 + 2 1) offers convenient high value bioisosteres drug discovery.The work spin-dependent reactivities insight into important synthesis, where reactive intermediate dictate outcome. hope may inspire others widen scope applications and/or reactions, furthermore, anticipate understandings also catalytic systems featuring

Language: Английский

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Photosensitizer-Free Photoinduced Ground-State Triplet Carbene-Assisted Persistent Aryloxy Radical Generation via Hydrogen Atom Transfer

Organic Letters, Journal Year: 2024, Volume and Issue: 26(41), P. 8674 - 8679

Published: Oct. 7, 2024

The traditional intermolecular O-H insertion strategy is typically associated with the reactivity exhibited by singlet spin state, or it can alter state from triplet to hydrogen bonding. Herein, we report diazoarylidene succinimide that generates a persistent ground-state carbene under visible light (Blue LED, 456 nm) without photosensitizer. This undergoes an intramolecular via atom transfer, forming aryloxy radical altering its and leading biologically relevant 2

Language: Английский

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Photocatalytic [2,3]-Sigmatropic Rearrangement Reactions of Ethyl Diazoacetate

Synlett, Journal Year: 2023, Volume and Issue: 35(09), P. 993 - 996

Published: Oct. 30, 2023

Abstract We describe a photocatalytic reaction of diazo compounds with allyl sulfides under visible-light conditions. In the presence Ru(bpy)3Cl2 as photocatalyst, [2,3]-sigmatropic rearrangement occurs that leads to formation homoallylic sulfides. This proceeds in acetone solvent, which is unusual carbene-transfer reactions, and it shows broad substrate scope allylic

Language: Английский

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