Synthesis and characterisation of starch cuprate

► Starch was esterified with ammonium tetrachlorocuprate(II) in the microwave-assisted and the convectional heating process. ► In the reaction the ligand exchange occurred. ► In the microwave-assisted process, a cuprate anion introduced into starch additionally coordinated water molecules. ► The microwave-assisted reaction significantly accelerated cupration. ► The deterioration of starch crystallinity influenced the cupration.