Umpolung of N-Tosylhydrazones: Synthesis of N-Cyano Tosylhydrazones and Their [3,3]-Sigmatropic Rearrangement to 2-Aminoimidazoles

Abstract

The umpolung of N-tosylhydrazones was reported for the first time. Synthesis of N-cyano tosylhydrazones was developed, and various N-cyano tosylhydrazones were prepared in good yields. An umpolung N-tosylhydrazones mechanism was proposed. Meanwhile, the [3,3]-sigmatropic rearrangement of N-cyano tosylhydrazones was examined, and the corresponding 2-aminoimidazoles were given.