Optimisation, scope and limitations of the synthesis of 5-aminoindolizines from oxazolo[3,2-a]pyridinium salts

We report on the optimisation of the synthesis of 5-aminoindolizines with respect to microwave heating, solvent, substrate/amine stoichiometry and base addition. A new improved protocol was developed and tested for its applicability to primary and secondary amines of varying nucleophilicity and steric demand.