General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides

We report a method for the synthesis of 2-substituted benzoxazoles from tertiary amides and 2-aminophenols in the presence of triflic anhydride (Tf<sub>2</sub>O) and 2-Fluoropyridine (2-F-Pyr). The cascade reaction involves the activation of the amide carbonyl group by Tf<sub>2<...

Full description

Saved in:
Bibliographic Details
Main Authors: Hongchen Li, Xingyong Wang, Fujun Zhao, Lu Wang, Songbao Fu
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/30/7/1510
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849769301754511360
author Hongchen Li
Xingyong Wang
Fujun Zhao
Lu Wang
Songbao Fu
author_facet Hongchen Li
Xingyong Wang
Fujun Zhao
Lu Wang
Songbao Fu
author_sort Hongchen Li
collection DOAJ
description We report a method for the synthesis of 2-substituted benzoxazoles from tertiary amides and 2-aminophenols in the presence of triflic anhydride (Tf<sub>2</sub>O) and 2-Fluoropyridine (2-F-Pyr). The cascade reaction involves the activation of the amide carbonyl group by Tf<sub>2</sub>O, nucleophilic addition, intramolecular cyclization, and elimination. Furthermore, we explore the scope of this method by varying both the amide and 2-aminophenol substrates, highlighting its versatility in the synthesis of a wide range of functionalized benzoxazole derivatives.
format Article
id doaj-art-ca343f8b31b044b2b5834a61b90a0baf
institution DOAJ
issn 1420-3049
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Molecules
spelling doaj-art-ca343f8b31b044b2b5834a61b90a0baf2025-08-20T03:03:28ZengMDPI AGMolecules1420-30492025-03-01307151010.3390/molecules30071510General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary AmidesHongchen Li0Xingyong Wang1Fujun Zhao2Lu Wang3Songbao Fu4CNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, ChinaCNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, ChinaCNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, ChinaCNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, ChinaCNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, ChinaWe report a method for the synthesis of 2-substituted benzoxazoles from tertiary amides and 2-aminophenols in the presence of triflic anhydride (Tf<sub>2</sub>O) and 2-Fluoropyridine (2-F-Pyr). The cascade reaction involves the activation of the amide carbonyl group by Tf<sub>2</sub>O, nucleophilic addition, intramolecular cyclization, and elimination. Furthermore, we explore the scope of this method by varying both the amide and 2-aminophenol substrates, highlighting its versatility in the synthesis of a wide range of functionalized benzoxazole derivatives.https://www.mdpi.com/1420-3049/30/7/1510benzoxazoleselectrophilic activationtriflic anhydridetertiary amides
spellingShingle Hongchen Li
Xingyong Wang
Fujun Zhao
Lu Wang
Songbao Fu
General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
Molecules
benzoxazoles
electrophilic activation
triflic anhydride
tertiary amides
title General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
title_full General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
title_fullStr General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
title_full_unstemmed General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
title_short General Synthesis of 2-Substituted Benzoxazoles Based on Tf<sub>2</sub>O-Promoted Electrophilic Activation of Tertiary Amides
title_sort general synthesis of 2 substituted benzoxazoles based on tf sub 2 sub o promoted electrophilic activation of tertiary amides
topic benzoxazoles
electrophilic activation
triflic anhydride
tertiary amides
url https://www.mdpi.com/1420-3049/30/7/1510
work_keys_str_mv AT hongchenli generalsynthesisof2substitutedbenzoxazolesbasedontfsub2subopromotedelectrophilicactivationoftertiaryamides
AT xingyongwang generalsynthesisof2substitutedbenzoxazolesbasedontfsub2subopromotedelectrophilicactivationoftertiaryamides
AT fujunzhao generalsynthesisof2substitutedbenzoxazolesbasedontfsub2subopromotedelectrophilicactivationoftertiaryamides
AT luwang generalsynthesisof2substitutedbenzoxazolesbasedontfsub2subopromotedelectrophilicactivationoftertiaryamides
AT songbaofu generalsynthesisof2substitutedbenzoxazolesbasedontfsub2subopromotedelectrophilicactivationoftertiaryamides