Isatogen and isatogenol: new precursors for facile preparation of highly functionalized heterocycles

Isatogens are a unique class of heterocyclic compounds with electrophilic character provided by carbon-heteroatom multiple bonds. Historically, isatogens have been used as dyes and bioactive molecules, and their recent applications have focused mainly on regio-and stereoselective transformations using a C=N bond. Because we realized that the rapid synthesis of multisubstituted indolines with fused ring systems could be a key methodology in our synthetic studies on complex alkaloids, we focused on isatogens as suitable precursors for highly functionalized indolines. In this account, cyanation and [3+2] cycloaddition for the construction of tetrasubstituted carbons and their application to alkaloid synthesis are described. 1 Introduction 2 Catalytic cyanation 3 [3+2] Cycloaddition of isatogenol 4 [3+2] Cycloaddition using nucleophilic olefins and its application 5 Conclusion