Regio- and site-selective activation of carbon-carbon double bonds to nucleophilic reagents. Cyclopropanation of vinylselenones with active methylene compounds
In the reactions with enolate anions, organoselenium moieties of aryl vinyl selenoxides and selenones have exhibited two important roles, e.g., activation of C=C bonds for conjugate addition reaction and behaviors as excellent leaving groups. Owing to such characteristic features, ketone enolates react with p-chlorophenyl vinyl selenoxide to afford the corresponding cyclopropyl ketones through an initial