Novel Electrophilic Species Equivalent to α-Keto Cations. Reactions of O,O-Diprotonated Nitro Olefins with Benzenes Yield Arylmethyl Ketones

Article abstract of DOI:10.1021/jo00265a001

The N,N-dihydroxyiminium carbenium ions formed by O,O-diprotonation of nitro olefins in a strong acid, trifluoromethanesulfonic acid (TFSA), are discrete and novel dipositively charged species.The dications formed from α-substitited nitroethylenes are reactive electrophiles to give α-arylated ketones in high yields.This constitutes a versatile synthetic method for the preparation of α-arylated ketones, which are difficult to synthesize by the conventional Friedel-Crafts reactions.