Transition metal-catalyzed synthesis of novel biologically relevant tryptophan analogues

Abstract

A synthetic approach to the synthesis of novel tryptophan derivatives and benzofuran-containing amino acids is detailed. The sequence starts from enzymatically resolved enantiopure acetylene-containing amino acids, of which the acetylene function can be efficiently transformed into the targeted 2-substited indole and benzofuran moieties via Sonogashira-type coupling and metal-catalyzed cyclization.