Convergent Routes to Pyrroles Exploiting the Unusual Radical Chemistry of Xanthates – An Overview

Abstract : Convergent routes to a variety of pyrroles involving radical additions of xanthates are described. Emphasis is placed on reactions leading to the formation of 1,4-diketones or 1,4-ketoaldehydes or their synthetic equivalents, which can then be condensed with ammonia or primary amines in a variation of the classical Paal–Knorr synthesis of pyrroles. The modification of pyrroles by direct radical addition is also discussed.