Iron-catalyzed selective oxidation of N-methyl amines: highly efficient synthesis of methylene-bridged bis-1,3-dicarbonyl compounds.

Methylene-bridged bis-1,3-dicarbonyl derivatives were synthesized efficiently by iron-catalyzed oxidative reactions of 1,3-dicarbonyl compounds and N,N-dimethylaniline. Bipyrazoles and substituted 1,4-dihydropyridine were obtained by the reactions of bis-1,3-dicarbonyl compounds with hydrazines and ammonium acetate, respectively.