Copper-Catalyzed [3 + 2] Cycloaddition Reaction of N -Hydroxysuccinimide Ester with Isocyanoacetates for the Synthesis of 4,5-Disubstituted Oxazoles.

The cycloaddition reaction of N -hydroxysuccinimide ester and isocyanatoacetate catalyzed by copper was described. A series of 4,5-disubstituted oxazole compounds, including ones derived from natural fatty acids, drugs, amino acids, and peptides, were obtained in moderate to high yields. The derivatization reaction was explored. The reaction mechanism was discussed.