Radical-Mediated Decarboxylative C–C and C–S Couplings of Carboxylic Acids via Iron Photocatalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(5), P. 1110 - 1115

Published: Jan. 26, 2024

Despite the significant success of decarboxylative radical reactions, catalytic systems vary considerably upon different acceptors, requiring renewed case-by-case reaction optimization. Herein, we developed an iron condition that enables highly efficient decarboxylation various carboxylic acids for a range transformations. This operationally simple protocol was amenable to wide array delivering structurally diverse oxime ethers, alkenylation, alkynylation, thiolation, and amidation products in useful excellent yields (>40 examples, up 95% yield).

Language: Английский

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Iron-Catalyzed Aerobic Carbonylation of Methane via Ligand-to-Metal Charge Transfer Excitation

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 6, 2025

The integration of ligand-to-metal charge transfer (LMCT) catalytic paradigms with radical intermediates has transformed the selective functionalization inert C-H bonds, facilitating use nonprecious metal catalysts in demanding transformations. Notably, aerobic carbonylation methane to acetic acid remains formidable due rapid oxidation methyl radicals, producing undesired C1 oxygenates. We present an iron terpyridine catalyst utilizing LMCT achieve exceptional C2/C1 selectivity through synergistic photoexcitation, generation, and carbonylation. Mechanistic studies highlight critical roles Fe(II) Fe-carbonyl complexes bypassing via a rebound-like pathway, unlocking unprecedented efficiency

Language: Английский

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Electrophotocatalytic perfluoroalkylation by LMCT excitation of Ag(II) perfluoroalkyl carboxylates

Science, Journal Year: 2023, Volume and Issue: 383(6680), P. 279 - 284

Published: Dec. 14, 2023

Molecular Ag(II) complexes are superoxidizing photoredox catalysts capable of generating radicals from redox-reticent substrates. In this work, we exploited the electrophilicity centers in [Ag(bpy)

Language: Английский

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Photoredox‐Catalyzed Decarboxylative Bromination, Chlorination and Thiocyanation Using Inorganic Salts

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(38)

Published: July 31, 2023

Abstract Decarboxylative halogenation reactions of alkyl carboxylic acids are highly valuable for the synthesis structurally diverse halides. However, many reported protocols rely on stoichiometric strong oxidants or electrophilic halogenating agents. Herein, we describe visible‐light photoredox‐catalyzed decarboxylative N ‐hydroxyphthalimide‐activated that avoid and use inexpensive inorganic halide salts as Bromination with lithium bromide proceeds under simple, transition‐metal‐free conditions using an organic photoredox catalyst no other additives, whereas dual photoredox‐copper catalysis is required chlorination chloride. The mild display excellent functional‐group tolerance, which demonstrated through transformation a range complex acid containing natural products into corresponding bromides chlorides. In addition, show generality photoredox‐copper‐catalyzed functionalization by extension to thiocyanation potassium thiocyanide, was applied thiocyanates.

Language: Английский

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Decarboxylative halogenation of aliphatic carboxylic acids catalyzed by iron salts under visible light

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(20), P. 2764 - 2767

Published: Jan. 1, 2024

A general method of visible light-induced decarboxylative halogenation aliphatic carboxylic acids catalyzed by iron is developed.

Language: Английский

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Iron photocatalysis via Brønsted acid-unlocked ligand-to-metal charge transfer

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 20, 2024

Abstract Reforming sustainable 3d-metal-based visible light catalytic platforms for inert bulk chemical activation is highly desirable. Herein, we demonstrate the use of a Brønsted acid to unlock robust and practical iron ligand-to-metal charge transfer (LMCT) photocatalysis multifarious haloalkylcarboxylates (C n X m COO − , = F or Cl) produce C radicals. This process enables fluoro-polyhaloalkylation non-activated alkenes by combining easily available Selectfluor as fluorine source. Valuable alkyl fluorides including potential drug molecules can be obtained through this protocol. Mechanistic studies indicate that real light-harvesting species may derive from in situ-assembly Fe 3+ H + acetonitrile solvent, which indeed increases efficiency LMCT between center via hydrogen-bond interactions. We anticipate acid-unlocked platform would an intriguing option execute compounds.

Language: Английский

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Multimodal Acridine Photocatalysis Enables Direct Access to Thiols from Carboxylic Acids and Elemental Sulfur

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(9), P. 6973 - 6980

Published: April 19, 2024

Development of photocatalytic systems that facilitate mechanistically divergent steps in complex catalytic manifolds by distinct activation modes can enable previously inaccessible synthetic transformations. However, multimodal remain understudied, impeding their implementation methodology. We report herein a access to thiols directly merges the structural diversity carboxylic acids with ready availability elemental sulfur without substrate preactivation. The transformation provides direct radical-mediated segue one most biologically important and synthetically versatile organosulfur functionalities, whose accessibility remains largely dominated two-electron-mediated processes based on toxic uneconomical reagents precursors. two-phase radical process is facilitated reactivity acridine photocatalysis enables both singlet excited state PCET-mediated decarboxylative carbon–sulfur bond formation unknown reductive disulfur cleavage photoinduced hydrogen atom transfer silane–triplet system. study points significant potential providing unexplored directions

Language: Английский

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Decarboxylative stereoretentive C–N coupling by harnessing aminating reagent

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 6, 2024

Abstract In recent decades, strategies involving transition-metal catalyzed carbon-carbon or carbon-heteroatom bond coupling have emerged as potent synthetic tools for constructing intricate molecular architectures. Among these, decarboxylative carbon-nitrogen formation using abundant carboxylic acids their derivatives has garnered notable attention accessing alkyl- arylamines, one of key pharmacophores. While several amination methods been developed, the involvement a common carboradical intermediate currently poses challenges in achieving stereospecific transformation toward chiral alkylamines. Herein, we present base-mediated, stereoretentive amidation by harnessing 1,4,2-dioxazol-5-one reactive and robust amidating reagent under transition-metal-free ambient conditions, encompassing all types primary, secondary tertiary acids, thereby providing access to important pharmacophore, α-chiral amines. This method exhibits high functional group tolerance, convenient scalability, ease applicability 15 N-isotope labeling, thus accentuating its utilities. Experimental computational mechanistic investigations reveal sequence elementary steps: i) nucleophilic addition carboxylate dioxazolone, ii) rearrangement form dicarbonyl N-hydroxy intermediate, iii) conversion hydroxamate, followed Lossen-type rearrangement, finally, iv) reaction situ generated isocyanate with leading C–N manner.

Language: Английский

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Acridine photocatalysis enables tricomponent direct decarboxylative amine construction

Chemical Science, Journal Year: 2024, Volume and Issue: 15(25), P. 9582 - 9590

Published: Jan. 1, 2024

Diverse amines and amino acids are now readily accessed from carboxylic acids, aldehydes, amine precursors in a direct decarboxylative reaction enabled by homogeneous triple catalytic system based on acridine photocatalysis.

Language: Английский

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A General Iron‐Catalyzed Decarboxylative Oxygenation of Aliphatic Carboxylic Acids

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(32)

Published: May 13, 2024

Abstract We report an iron‐catalyzed decarboxylative C(sp 3 )−O bond‐forming reaction under mild, base‐free conditions with visible light irradiation. The transformation uses readily available and structurally diverse carboxylic acids, iron photocatalyst, 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) derivatives as oxygenation reagents. process exhibits a broad scope in acids possessing wide range of stereoelectronic properties functional groups. developed was applied to late‐stage series bio‐active molecules. leverages the ability complexes generate carbon‐centered radicals directly from by photoinduced carboxylate‐to‐iron charge transfer. Kinetic, electrochemical, EPR, UV/Vis, HRMS, DFT studies revealed that TEMPO has triple role reaction: reagent, oxidant turn over Fe‐catalyst, internal base for acid deprotonation. obtained adducts represent versatile synthetic intermediates were further engaged C−C C‐heteroatom reactions using commercial organo‐photocatalysts nucleophilic

Language: Английский

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