A novel and efficient cascade method has been developed for the diastereoselective preparation of trifluoromethyl-containing dihydrooxazoles in high yields. The reaction was applicable to electron-deficient, electron-rich arenes, heteroarenes, and alkyl groups. Control experiments were conducted to explore the reaction mechanism and reveal that the byproduct formed in situ is the catalyst for this reaction and a tether derived from trifluoropyruvate is a key intermediate for this reaction.