Sequential Sonogashira and Suzuki cross-coupling reactions in the indole and indazole series

Abstract

3-Iodoindoles, 5-bromo-3-iodoindoles and 5-bromo-3-iodoindazoles have been studied with respect to their reactivity and selectivity in palladium catalyzed Sonogashira and Suzuki cross-coupling reactions. As a result, sequential Sonogashira-Sonogashira, Sonogashira-Suzuki, and Suzuki-Sonogashira reactions with 5-bromo-3-iodoindoles or indazoles were used to obtain a large range of new functionalized indoles and indazoles, which are potential 5-HT receptor ligands.