International Journal of Molecular Sciences (Nov 2022)
Acid-Switchable Synthesis of Trifluoromethylated Triazoles and Isoxazoles via Reaction of CF<sub>3</sub>-Ynones with NaN<sub>3</sub>: DFT Study of the Reaction Mechanism
Abstract
A detailed study of the reaction of CF3-ynones with NaN3 was performed. It was found that the reaction permits the selective synthesis of either 4-trifluoroacetyltriazoles or 5-CF3-isoxazoles. The chemoselectivity of the reaction was switchable via acid catalysis. The reaction of CF3-ynones with NaN3 in EtOH produced high yields of 4-trifluoroacetyltriazoles. In contrast, the formation of 5-CF3-isoxazoles was observed under catalysis by acids. This acid-switchable procedure can be performed at sub-gram scale. The possible reaction mechanism was supported by DFT calculations. The synthetic utility of the prepared 4-trifluoroacetyltriazoles was demonstrated.
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