Oxidative Olefination of Secondary Amines­ with Carbon Nucleophiles

An unprecedented olefination reaction of secondary amines with carbon nucleophiles has been developed through C–N/C–H functionalization under metal‐free oxidative conditions. In the presence of a stoichiometric amount of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), a range of secondary N‐alkylanilines smoothly underwent oxidative olefination with 2‐alkylazaarenes, acetophenone, and malononitrile to give structurally diverse polysubstituted alkenes in moderate to excellent yields with excellent (E) selectivity. Preliminary mechanistic studies revealed that the oxidative olefination reaction proceeds through amine oxidation followed by imine olefination. A range of secondary N‐alkylanilines smoothly underwent DDQ‐promoted oxidative olefination with 2‐alkylazaarenes, acetophenone, and malononitrile to give structurally diverse alkenes in moderate to excellent yields with excellent (E) selectivity. Mechanistically, the reaction proceeds through amine oxidation followed by imine olefination (DDQ = 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone).