Electrophilic 1,2-Addition of Oxoammonium Salts to Olefins

A new reaction of oxoammonium salt is demonstrated. Addition of oxoammonium salts (1) to electron-rich olefins (2) such as vinyl ethers and enamines rapidly proceeded to give corresponding 1,2-adducts (3) in high yields. The adducts 3 formed were further transformed by treatment with sodium ethoxide to isolable substitution products (4) in one pot reaction.