Ring-expansion reaction for the synthesis of 2-(trifluoromethyl)oxazoles and 3-(trifluoromethyl)-1, 2, 4-triazines. (28th September 2022)

• Record Type: Journal Article
• Authors: Teng, Yun; Fang, Tingyu; Lin, Zitong; Qin, Lu; Jiang, Mengfan; Wu, Wei; You, Yi; Weng, Zhiqiang
• Is Part Of: Tetrahedron letters. Volume 107(2022)
• Publication Date: 2022-09-28
• Subjects: Trifluoroacetic anhydride -- Trifluoromethyl -- 1, 2, 4-Triazine -- Oxazole -- Ring-expansion reaction; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2022.154100
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: The synthesis of 2-(trifluoromethyl)oxazoles through ring-expansion reaction of 2 H -azirine with trifluoroacetic anhydride is reported. The 2-(trifluoromethyl)oxazole compounds can be easily converted into 3-(trifluoromethyl)-1, 2, 4-triazines through hydrazinolysis reaction. Highlights: A method for synthesis of 2-(trifluoromethyl)oxazoles and 3-(trifluoromethyl)-1, 2, 4-triazines was developed. Various trifluoromethyl oxazoles and triazines were synthesized in moderate to excellent yields. A variety of functional groups were tolerated. Abstract: A ring-expansion reaction of 2 H -azirine with trifluoroacetic anhydride for the synthesis of 2-(trifluoromethyl)oxazoles is disclosed. The reaction features readily available reactants, relatively mild conditions, and high yields of products. The generated 2-(trifluoromethyl)oxazole core could be easily converted into 3-(trifluoromethyl)-1, 2, 4-triazines through hydrazinolysis reaction.