Synthesis of (Hetero)Aroyl Fluorides via a Mild Amides C−N Bond Cleavage

Abstract

Amides, such as N-benzoylsaccharin, N,N-diBocbenzamide, and N-phenyl-N-tosylbenzamides reacted with Et 3 N . 3HF to provide the corresponding acyl fluorides in good yields. The reaction was conducted under environmentally friendly conditions using i-PrOAc as the solvent. Moreover, the reaction was performed at room temperature and did not require a transition-metal catalyst or additives. The methodology showed functional group tolerance toward amines, alkoxy, halides, ketones, esters, and aldehydes.

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

“…Improvements to the classical approach to the deoxyfluorination of carboxylic acids using HF and inorganic fluorides have also been made in recent years . Prakash et al developed a new phosphorus-based protocol for the transformation of carboxylic acids to acyl fluorides using Et 3 N-HF .…”

Palladium and Copper‐Catalyzed Friedel–Crafts Acylation with Activated Amides

“…[6] In 2018, our group reported the nickel-catalyzed transamidation of secondary amides, producing transamidated secondary and tertiary amides. [7] Since then, both transition metal-catalyzed and metal-free conditions have been applied to facilitate the synthesis of a diverse array of compounds, including primary amides, [8] β-keto amides, [9] β-keto esters, [10] β-keto nitriles, [11] 1,3-diketones, [12] acyl fluorides, [13] and acyl azides. [14] The use of activated amides in transformation reactions has received significant attention in recent years.…”