The synthesis of polysubstituted indoles from 3-bromo-2-indolyl phosphates

Abstract

A novel methodology for the synthesis of functionalised indoles based on the cross-coupling reactions of 3-bromo-2-indolyl phosphates is described. The preparation involves the conversion of easily available 2-oxindoles to 3,3-dibromo-2-oxindoles followed by the Perkow reaction affording 3-bromo-2-indolyl phosphates. Then bromine atom is substituted regioselectively by the Suzuki coupling reaction. We observed that aluminum chloride promoted the reaction of 3-substituted-2-indolyl phosphates with organozinc reagents furnishing 2,3-disubstituted indoles as final products. The overall diversity and efficiency of the methodology was demonstrated by the synthesis of bioactive molecule from easily available substances.