New indolizine template from the Ugi reaction

Ugi reactions and [3+2] cycloaddition of pyridinium salts have been associated to provide an efficient multicomponent access to indolizines. The pyridinium salts are formed by an Ugi reaction using chloroacetic acid and propargylamine followed by pyridine addition on the Ugi adduct. The coupling of these salts with aryl iodides gives directly indolizine derivatives in a Sonogashira-cycloaddition-oxidation reaction cascade.