A new a chitin-supported KI catalyst system has shown highly efficient activity towards the cycloaddition of CO2 to epoxides. The cooperative effect of this catalyst system is enhanced when a little amount of DBU as additive is added at a KI:DBU weight ratio of 8:2, which enables scaling-up procedures to a multigram level, using a widely available biopolymer such as chitin. Furthermore, the same catalyst composition is able to activate the trans-esterification of propylene carbonate to dimethyl carbonate under smooth reaction conditions using a KI:DBU weight ratio 1:1. A combination of DBU with a chitin-supported KI catalyst system has shown highly efficient activity towards the cycloaddition of co(2) to epoxides. the synergetic effect in this three-component catalyst system is enhanced at a KI:DBU weight ratio of 8:2, which enables scaling-up procedures to a multigram level, using a widely available biopolymer such as chitin. Furthermore, the same catalyst composition is able to activate the trans-esterification of propylene carbonate to dimethyl carbonate under smooth reaction conditions. [GRAPHICS] .