Balancing between Heterogeneity and Reactivity in Porphyrin Chromium-Cobaltate Catalyzed Ring Expansion Carbonylation of Epoxide into β-Lactone.

The synthesis of a unique heterogeneous catalyst that combines the functionality of a homogeneous catalyst and the advantages of a heterogeneous catalytic process is a continuing goal in various industrially applicable reactions. Here, we report heterogenization of homogeneous catalyst for lactone production from epoxide carbonylation through a facile polymerization using Friedel-Crafts reaction. A correlation between reactivity and degree of heterogeneity has been deduced by synthesizing different sized polymeric catalysts. The partially polymerized catalyst showed a remarkable initial turnover frequency of 400 h, and the fully polymerized catalyst displayed excellent selectivity during recycling with a total turnover number of 4100.