Catalytic Domino Three-Component Synthesis of Functionalized Heterocycles from Carbon Dioxide

A catalytic domino, three-component reaction has been developed for the transformation of carbon dioxide into functionalized six-membered cyclic carbonates. The catalytic process combines an initial carboxylative cyclization of beta-epoxy alcohols followed by an oxa-Michael reaction affording an unparalleled scope of heterocyclic structures. The wide range of functional groups, including free-alcohols, empowers the access to a range of products including C11-oxo-based bicyclic heterocycles. The versatility of these functionalized carbonates is further complemented by a series of synthetic diversifications. Control experiments are consistent with the first step of this domino process being promoted by a binary Lewis acid/base catalyst, while the second stage only requires catalytic base. A catalytic domino process has been developed for larger-ring, functionalized cyclic carbonates with various types of functional groups and involves the intermediacy of a free-alcohol based six-membered cyclic carbonate. The domino protocol is propelled by a combination of an Al(III) complex and N-methyl-morpholine as supported by various control experiments.image