A facile and efficient ultrasound-assisted synthesis of novel dispiroheterocycles through 1,3-dipolar cycloaddition reactions

A facile and efficient one-pot three-component procedure for synthesis of novel dispirooxindolecyclo[pyrrolo[1,2-c]thiazole-6,5′-thiazolidine] derivatives without any catalysts under ultrasonic condition has been developed. Combining with the advantages of sonochemistry, such as mild reaction conditions, good yield and short reaction times, we have made a progress on construction of novel disiproheterocyclic compounds via the 1,3-dipolar cycloaddition of azomethine ylides. Several experiments were especially carried out for investigating the acceleration mechanism of ultrasound on the cycloaddition.

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► Ultrasonic-assisted synthesis of novel dispiroheterocyclic compounds.
► Ultrasonic irradiation was found to have beneficial effect on the synthesis.
► The effect of frequency and temperature of ultrasound irradiation on the reaction was studied.
► The role and acceleration mechanism of sonication in the present system was discussed.
► Mechanistic study of ultrasonic-assisted synthesis of novel dispiroheterocycle compounds.