Double Ring-Expanding Carbonylation Using an In Situ Generated Aluminum Phthalocyanine Cobalt Carbonyl Complex

Abstract

The ring-expanding carbonylation of epoxides provides an efficient one-step procedure for synthesizing beta-lactones and succinic anhydride derivatives. Although porphyrin-based catalysts generally show excellent catalytic activities in the ring-expanding carbonylation of epoxides, the application of porphyrin catalysts is limited owing to the low yield and high cost of preparing porphyrins. This study aims to propose a new and highly efficient catalytic system for the carbonylation of propylene oxide (PO) using an in situ generated active catalyst from cost-effective and readily available aluminum phthalocyanine chloride (AlPcCl) and dicobalt octacarbonyl (Co-2(CO)(8)). The catalyst showed not only excellent catalytic activities of single carbonylation but also double carbonylation resulting in anhydride by judicious choice of reaction parameters, such as reaction temperature and the ratio of PO to catalyst. This is the first report on the use of an in situ generated catalyst for the one-pot double carbonylation of epoxide to anhydride.