Ugi post-condensation copper-triggered oxidative cascade towards pyrazoles

Abstract

International audiencePyrazolidinones were prepared in a two-step sequence starting from a-hydrazonocarboxylic acids. After a four-component Ugi coupling, the resulting hydrazone was engaged in a copper triggered [3 + 2] cycloaddition/aerobic oxidation cascade. © 2011 Santos et al; licensee Beilstein-Institut