Addition of activated olefins to cyclic N-acyliminium ions in ionic liquids

Abstract Organoindate(III) ionic liquid (BMI·InCl 4 ) was successfully employed in the nucleophilic addition of allyltrimethylsilane, silyl enol ethers and ketene silyl acetals to in situ generated cyclic N -acyliminium ions at room temperature without the need of an external Lewis acid. The corresponding α-substituted heterocycles were obtained in good yields and the recovered ionic liquid phase could be reused at least three times.