The Ugi reaction as the green alternative towards active pharmaceutical ingredients

Α sustainable access to therapeutics is today imperative. More than ever, synthetic organic chemistry has to embrace all aspects of green chemistry. The utility of multicomponent reactions especially the Ugi reaction is an established approach in drug discovery. Their diversity, speed and effectiveness, combined with their compatibility with the green chemistry principles, render this type of chemistry very often an alternative to the multistep linear synthetic pathways to active pharmaceutical ingredients. This critical review compares green metrics, such as E-factor (environmental factor), AE (atom economy) and PMI (process mass intensity) factors, of the industrial and MCR syntheses of six well-known commercial drugs.