Microwave-mediated synthesis of a cyclic heptapeptoid through consecutive Ugi reactions

The combination of consecutive Isocyanide-based Multicomponent Reactions (IMCRs) allowed the synthesis of a cyclic heptapeptoid in a reduced number of steps. Herein, we describe this efficient approach using four consecutive Ugi reactions, being three Ugi four-center, four-component reactions, and one Ugi four-center, three-component reaction. Our strategy involved eight steps of which seven in a row were microwave-assisted with reaction times of 3–5?min and yields ranging from 88 to 98%.