Synthesis of Functionalized Pseudopeptides through Five-Component Sequential Ugi/Nucleophilic Reaction of N‑Substituted 2‑Alkynamides with Hydrazides

Five-component sequential Ugi/nucleophilic addition reaction of aromatic aldehydes, primary amines, propiolic acid, isocyanides, and hydrazides has been developed in order to access polyfunctional pseudopeptides. The reaction may proceed through formation of N-substituted 2-alkynamides as intermediates. This process is found to be mild and operationally simple with broad substrate scope.