A cascade approach to 3D cyclic carbamates via an ionic decarboxylative functionalization of olefinic oxamic acids.

An m-CPBA-mediated intramolecular epoxidation-decarboxylative alkoxylation cascade reaction of olefinic oxamic acids has been developed. The distinct ionic decarboxylative mechanism was preliminarily revealed. The protocol features mild reaction conditions and operational simplicity, allowing the construction of diverse medicinally valuable 5-7 membered 3D cyclic carbamate architectures in moderate to high yields.