TMSOTf-Catalyzed C2-Sulfenylation of Indole Alkaloids Using N -Sulfenylsuccinimides: An Approach for the Total Synthesis of Isatindigotindolosides.

A TMSOTf-catalyzed C2-sulfenylation of indole alkaloids with N -sulfenylsuccinimides has been developed. This straightforward, metal-free, and cost-effective catalytic system produces valuable 2-thioindole derivatives with yields ranging from moderate to excellent. The synthetic applicability demonstrated includes the total syntheses of isatindigotindolosides I - IV .