Cascade Transformation of Carbon Dioxide and Alkyne-1,<i>n</i>-diols into Densely Substituted Cyclic Carbonates

A silver-catalyzed cascade conversion of modular alkyne-1,n-diols and carbon dioxide has been developed allowing for the selective formation keto-functionalized cyclic carbonates. The protocol is characterized by its operational simplicity, excellent scope carbonate-based heterocycles, mild reaction conditions. In situ IR studies, control experiments, detailed computational analysis these manifolds reveal intermediacy an α-alkylidene carbonate that intercepted intramolecular alcohol nucleophile. synthetic potential this conceptually attractive CO2 transformation demonstrated in preparation larger ring carbonates their thermal rearrangement to sterically crowded, five-membered fused products.