Divergent synthesis of 2-methylthioindole and 2-unsubstituted indole derivatives mediated by SOCl 2 and dimethyl/diethyl sulfoxides.

A metal-free divergent synthesis of indole compounds dependent on a reagent via intramolecular C(sp 2 )-H amination was described. The reaction of 2-vinylanilines with DMSO/SOCl 2 at 70 °C was found to give 2-thiomethylindoles, while replacing DMSO with diethyl sulfoxide afforded 2-unsubstituted indoles in a highly selective manner.