General Synthesis of 2-Substituted Benzoxazoles Based on Tf2O-Promoted Electrophilic Activation of Tertiary Amides

• Published in: Molecules (Basel, Switzerland) Vol. 30; no. 7; p. 1510
• Main Authors: Li, Hongchen, Wang, Xingyong, Zhao, Fujun, Wang, Lu, Fu, Songbao
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 28.03.2025
• Subjects: benzoxazoles; electrophilic activation; Methods; Nitrogen; tertiary amides; triflic anhydride

We report a method for the synthesis of 2-substituted benzoxazoles from tertiary amides and 2-aminophenols in the presence of triflic anhydride (Tf2O) and 2-Fluoropyridine (2-F-Pyr). The cascade reaction involves the activation of the amide carbonyl group by Tf2O, nucleophilic addition, intramolecul...