Schwartz's Reagent-Mediated Regiospecific Synthesis of 2,3-Disubstituted Indoles from Isatins.

An expeditious, functional group-tolerant synthesis of indoles from isatins is described. Isatins are treated with Grignard reagents to yield oxindoles. These, in turn, are reduced with Schwartz's reagent and subjected to nucleophile addition and dehydration to yield 2,3-disubstituted indoles regiospecifically. This represents a divergent approach to the synthesis of these medicinally and synthetically important compounds.