Au-allenylidene promoted decarboxylative annulation to access unsaturated γ-lactams/lactones.

A novel Au-allenylidene promoted decarboxylative annulation by intramolecular α-nucleophilic addition has been disclosed. The unsaturated cyclic ethynylethylene carbamates/carbonates can be converted to unique nucleophiles attached with alkylidene ketenes by sequential decarboxylation and oxidation processes. Such alkylidene ketenes can be rapidly trapped by intramolecular α-attacking annulation to generate potential biological active unsaturated γ-lactams/lactones with broad scope, facile post-modification, high regioselectivity and efficiency.