Polyethylene glycol (PEG 400) embedded potassium bromide i.e. [K+{PEG}Br-] was found to be an extremely simple, highly efficient and recyclable promoter/medium for the cycloaddition reaction of epoxides and aziridines to CO2 to give corresponding cyclic carbonates and oxazolidinones, respectively, under mild conditions without utilization of additional organic solvents or additive. The catalyst worked well for a wide variety of substrates and could be recovered easily and reused without significant loss of catalytic activity and selectivity.