Pillar[5]arene-segregated ion pairs for enhanced cycloaddition of epoxides with CO.

A supramolecular approach using a polyviologen-pillar[5]arene complex as segregated ion pairs was shown to be highly efficient for the conversion of CO with epoxides into cyclic carbonates without the need for metals or solvents. The enhanced catalytic performance was achieved by cooperative ion pair segregation and CO fixation.