Chemically modified expended starch grafted Ni-acetylacetonate/TBAB: An effective reusable catalytic combination for the cycloaddition of carbon dioxide to epoxides

Starch is renewable, biodegradable and relatively inexpensive material that has been used for the grafting of nickel(II) acetylacetonate by covalent linkage. The prepared material in combination with tetrabutyl ammonium bromide is found to be a very active, selective and recyclable catalytic system for the cycloaddition of CO2 and epoxides without co-solvent under relatively mild reaction conditions. Importantly, the starch grafted nickel catalyst and TBAB are easily recovered after the reaction and reused many times without any loss in catalytic activity.