2-Arylsilacyclobutane as a Latent Carbanion Reacting with CO2.

An electronically neutral 2-arylsilacyclobutane generates a nucleophilic carbanion at room temperature through cleavage of the benzylic C-Si bond when simply dissolved in polar aprotic solvents such as N,N-dimethylformamide (DMF). The nucleophilic species is capable of capturing carbon dioxide to furnish a silalactone. The carboxylation reaction is unique in that no additional activating agents are required.