Palladium-Catalyzed Oxidation-Hydroxylation and Oxidation-Methoxylation of N-Boc Indoles for the Synthesis of 3-Oxoindolines

Abstract

The palladium-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles for the synthesis of tert-butyl 2-hydroxy(methoxy)-3-oxoindoline-1-carboxylates and their derivatives is developed. The process occurs readily using PdCl2 as the catalyst and acetonitrile as the solvent to afford 3-oxoindolines in moderate to high yields. A mechanism for this Pd-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles is proposed.