BF₃-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(20), С. 11012 - 11018

Опубликована: Май 12, 2023

A BF3-catalyzed atom-economical fluorocarbamoylation reaction of alkyne-tethered carbamoyl fluorides is reported. The catalyst acts as both a fluoride source and Lewis acid activator, thereby enabling the formal insertion alkynes into strong C-F bonds through halide recycling mechanism. developed method provides access to 3-(fluoromethylene) oxindoles γ-lactams with excellent stereoselectivity, including fluorinated derivatives known protein kinase inhibitors. Experimental computational studies support stepwise mechanism for involving turnover-limiting cyclization step, followed by internal transfer from BF3-coordinated adduct. For methylene oxindoles, thermodynamically driven Z-E isomerization facilitated transition state aromatic character. In contrast, this stabilization not relevant γ-lactams, which results in higher barrier exclusive formation Z-isomer.

Язык: Английский

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Photoinduced N-Heterocyclic Nitrenium-Catalyzed Single Electron Reduction of Acyl Fluorides for Phenanthridine Synthesis

Organic Letters, Год журнала: 2023, Номер 25(3), С. 565 - 568

Опубликована: Янв. 13, 2023

Acyl fluorides are versatile reagents in organic synthesis. However, there is no precedent to employ acyl as radical precursors. We herein report an N-heterocyclic nitrenium iodide salt-catalyzed photoreduction of produce radicals, which could react with 2-isocyanobiaryls afford various carbonyl phenanthridines.

Язык: Английский

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Taking Olefin Metathesis to the Limit: Stereocontrolled Synthesis of Trisubstituted Alkenes

Accounts of Chemical Research, Год журнала: 2023, Номер 56(18), С. 2426 - 2446

Опубликована: Авг. 29, 2023

ConspectusIn this Account, we share the story of development catalytic olefin metathesis processes that efficiently deliver a wide range acyclic and macrocyclic E- or Z-trisubstituted alkenes. The tale starts with us unveiling, in collaboration Richard Schrock his team, blueprint 2009 for design kinetically controlled Z-selective reactions. This paved way Mo-, W-, Ru-based catalysts strategies synthesizing countless linear Z-olefins. Six years later, 2015, found abundant Z-alkene feedstocks, such as oleic acid, can be directly transformed to high-value more difficult-to-access alkenes through cross-metathesis reaction promoted by Ru-catechothiolate complex had developed; approach, later coined stereoretentive metathesis, was extended synthesis E-alkenes.It all about disubstituted until when 2017 addressed challenge accessing stereodefined Z- E-trisubstituted alkenes, key medicine materials research. These transformations most effectively catalyzed Mo monoaryloxides pyrrolide (MAP) chloride (MAC) complexes. A central aspect advance is merging which delivered trisubstituted alkenyl fluorides, chlorides, bromides cross-coupling. used various combinations, thereby enabling access assorted alkene. Ensuing work led emergence other involving substrates purchased high stereoisomeric purity, notably Z-trihalo Trisubstituted olefins, Z E, bearing chemoselectively stereoretentively alterable F,Cl-terminus B(pin),Cl-terminus may, thus, easily reliably synthesized. Methods preparation bromide regioisomers α,β-unsaturated carboxylic thiol esters, nitriles, acid fluorides followed, along ring-closing reactions afford olefins. E-Macrocyclic including those contain little no entropic support cyclization (minimally functionalized) and/or are disfavored under substrate-controlled conditions, now utility latest chapter history has been highlighted applications several biologically active compounds, well their analogues, marked one site-specifically incorporated fluorine atoms but higher energy otherwise unobtainable conformers.The investigations discussed here, represent every method reported thus far preparing olefin, underscore inimitable power Mo-based catalysts. Account also showcases variety mechanistic attributes─some first time, each instrumental solving problem. Extensive knowledge nuances will needed if address successfully next challenging problem, namely, may synthesize tetrasubstituted especially readily modifiable, purity.

Язык: Английский

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Mechanochemical Deoxyfluorination of Carboxylic Acids to Acyl Fluorides and Successive Mechanochemical Amide Bond Formation

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 12(9), С. 3565 - 3574

Опубликована: Фев. 16, 2024

Diverse methods have been reported for the synthesis of acyl fluorides; however, an environmentally benign method fluorides remains underdeveloped. In this study, we developed solvent-free mechanochemical deoxyfluorination carboxylic acids to mediated by 1,1,2,2-tetrafluoroethyl-N,N-dimethylamine (TFEDMA) using a ball mill. This facilitated high product yields in short reaction times even sterically challenged acids. We also realized coupling and amines as well TFEDMA-mediated direct with via sequential one-pot deoxyfluorination/coupling pathway. Furthermore, protocol was expanded include peptide synthesis. The efficiency protocol, terms speed, characteristics, favorable E-factor, aligns requirements current environmental policies.

Язык: Английский

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Cationic Rhodium(I) Tetrafluoroborate Catalyzed Intramolecular Carbofluorination of Alkenes via Acyl Fluoride C−F Bond Activation**

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(23)

Опубликована: Март 31, 2023

The C-F bond of acyl fluorides can be cleaved and added across tethered alkenes in the presence a cationic rhodium(I) tetrafluoroborate catalyst. This 1,2-carbofluorination reaction offers powerful method for synthesis tertiary alkyl fluoride derivatives with an atom economy 100 %. Mechanistic studies indicate that concerted action rhodium cation anion is key success this catalytic cleavage formation bonds controlled manner.

Язык: Английский

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Unlocking the Power of Acyl Fluorides: A Comprehensive Guide to Synthesis and Properties

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(18)

Опубликована: Март 6, 2024

Abstract Acyl fluorides have emerged as versatile reagents in various synthetic endeavors, offering a range of advantages over their counterparts, acyl chlorides. This study delves into the properties and reactivity fluorides, particularly reaction with amines alcohols, to elucidate distinct characteristics. We also introduce facile practical synthesis from stable solution CF 3 O − salt. Additionally, we establish an efficient one‐pot process for direct preparation amides or esters corresponding acids showcasing remarkable efficiency these transformations.

Язык: Английский

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1,2-Diacylation of Alkynes Using Acyl Fluorides and Acylsilanes by P(III)/P(V) Catalysis

Organic Letters, Год журнала: 2023, Номер 25(2), С. 336 - 340

Опубликована: Янв. 5, 2023

We report herein the phosphine-catalyzed 1,2-diacylation of alkynes using acyl fluorides and acylsilanes as sources. The key to success reaction is a formal oxidative addition-ligand metathesis-reductive elimination cycle based on phosphine redox catalysis, which allows for installation two different groups into an alkyne in regioselective manner.

Язык: Английский

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Recent Advances in the Synthesis and Transformation of Carbamoyl Fluorides, Fluoroformates, and Their Analogues

The Chemical Record, Год журнала: 2023, Номер 23(9)

Опубликована: Апрель 26, 2023

Abstract Carbamoyl fluorides, fluoroformates, and their analogues are a class of important compounds have been evidenced as versatile building blocks for the preparation useful molecules in organic chemistry. While major achievements were made synthesis carbamoyl last half 20 th century, an increasing number reports focused on using O/S/Se=CF 2 species or equivalents fluorocarbonylation reagents direct construction these from parent heteroatom‐nucleophiles recent years. This review mainly summarizes advances typical application by halide exchanges reactions since 1980.

Язык: Английский

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C−F Bond Insertion: An Emerging Strategy for Constructing Fluorinated Molecules

Chemistry - A European Journal, Год журнала: 2024, Номер 30(20)

Опубликована: Янв. 25, 2024

C-F Insertion reactions, where an organic fragment formally inserts into a carbon-fluorine bond in substrate, are highly attractive, yet largely unexplored, methods to prepare valuable fluorinated molecules. The inherent strength of bonds and the resulting need for large thermodynamic driving force initiate cleavage often leads sequestering released fluoride unreactive by-product. Recently, however, several groups have succeeded overcoming this challenge, opening up study insertion as efficient atom-economical approach compounds. In article, recent breakthroughs discussed focusing on key conceptual advances that allowed both subsequent incorporation product.

Язык: Английский

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Palladium-Catalyzed Decarbonylative Nucleophilic Halogenation of Acid Anhydrides

Catalysts, Год журнала: 2025, Номер 15(2), С. 191 - 191

Опубликована: Фев. 19, 2025

In this study, we developed a palladium-catalyzed decarbonylative nucleophilic halogenation reaction using inexpensive and readily available acid anhydrides as substrates. This approach effectively circumvents the instability of acyl chlorides low reactivity fluorides. The Pd/Xantphos catalyst system exhibited excellent compatibility with thermodynamically kinetically challenging reductive elimination C–X bonds (X = I, Br, Cl) from Pd(II) intermediates. Notably, for electron-donating substrates, adopting an open significantly improved efficiency. positive effect may be due to reversible nature CO insertion deinsertion, which helps direct toward desired pathway by allowing generated exit system. Mechanistic studies suggest that proceeds through highly reactive halide intermediate, followed unimolecular fragment coupling (UFC) via decarbonylation or alternative involving formation activated anionic palladate complex in presence lithium halide.

Язык: Английский

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