Recent Advances in C–F Bond Activation of Acyl Fluorides Directed toward Catalytic Transformation by Transition Metals, N-Heterocyclic Carbenes, or Phosphines

Abstract

Studies on the activation of carbon–fluorine bonds have been reported intensively in recent years. Among them, acyl fluorides have been utilized as versatile reagents for acylation, arylation, and even fluorination. In this review, we focus on acyl fluorides as compounds with carbon-fluorine bonds and review recent advances in strategies for the activation of their C-F bonds, including 1) transition metal catalysis, 2) N-heterocyclic carbene (NHCs) catalysis, 3) organophosphine catalysis, and 4) classical nucleophilic substitution reactions.

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

“…We then turned to the question regarding acid fluorides, which were shown to possess a unique reactivity profile . CM involving 52 and Mo­(MAC) complexes, particularly Mo­(MAC)-1e , was the most efficient (e.g., 53a – d ; Scheme c).…”

“…44 We then turned to the question regarding acid fluorides, which were shown to possess a unique reactivity profile. 46 CM involving 52 and Mo(MAC) complexes, particularly Mo-(MAC)-1e, was the most efficient (e.g., 53a−d; Scheme 20c). We initially linked this to the diminished Lewis basicity of the πcloud in an α,β-unsaturated acid fluoride needing a more Lewis acidic Mo(MAC) catalyst.…”

BF3-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling

“…While new synthetic applications of acyl fluorides have been widely developed, the established chemistry of related carbamoyl fluorides has been largely limited because of their increased stability. Accordingly, strong nucleophiles are often required for simple substitution reactions (Scheme a). − In the context of transition-metal-catalyzed reactions, few reports on the cross-coupling of carbamoyl fluoride electrophiles have been disclosedall of which require a Ni 0 catalyst to facilitate the challenging C–F bond oxidative addition step .…”

Elemental Sulfur-Mediated Transformation of Carboxylic Acids to Acyl Fluorides by Electrophilic Fluorinating Reagent, Selectfluor

“…Interestingly, with the rapid progress of organic synthetic techniques, particularly the selective C−F bond activation under transition-metal catalysis, 2 acyl fluorides have increasingly become the preferred precursors over other acyl halides in decarbonylative and nondecarbonylative reactions. 3 In addition, acyl fluorides act as a fluorine sources in fluorination reactions; 4 one recent achievement in this regard is the nucleophilic aromatic substitution of aryl halides by acyl fluorides. 4a These properties have motivated the development of efficient synthetic methodologies for the synthesis of acyl fluorides.…”

“…Acyl fluorides (R-COF) have recently attracted considerable attention as a valuable platform to access numerous organic compounds. − Acyl fluorides are typically less reactive than conventional acyl halides (R-COX, X = Cl, Br, I) owing to their higher stability, making them easy to handle. Interestingly, with the rapid progress of organic synthetic techniques, particularly the selective C–F bond activation under transition-metal catalysis, acyl fluorides have increasingly become the preferred precursors over other acyl halides in decarbonylative and nondecarbonylative reactions . In addition, acyl fluorides act as a fluorine sources in fluorination reactions; one recent achievement in this regard is the nucleophilic aromatic substitution of aryl halides by acyl fluorides .…”