A covalent triazine framework-based heterogenized Al–Co bimetallic catalyst for the ring-expansion carbonylation of epoxide to β-lactone

Difficulties in product separation and ineffective recycling of the homogenous catalyst deter the mass production of β-lactones via carbonylation of epoxides. Herein, we address these issues, for the first time, using a recyclable heterogenized catalyst [bpy-CTF-Al(OTf)2][Co(CO)4] that efficiently converts propylene oxide (PO) to β-butyrolactone with high selectivity.