14 A New Iron Complex [Fe(DMF)_3Cl_2][FeCl_4] And Oxidative Coupling Reactions
Details
A new method for the intramolecular oxidative coupling and intermolecular oxidative coupling by a new iron complex [Fe(DMF)_3Cl_2][FeCl_4] prepared from ferric chloride and dimethylformamide (DMF) which gives the oxidation products in high yield under mild condition and which avoids the formation of polymeric compounds in minimum amounts, was investigated. A. Synthesis and characterization of a new iron complex: The iron complex was synthesized from ferric chloride and DMF in ether in yield 95.5%. The molecular formula for this complex was reduced to [Fe(DMF)_3Cl_2][FeCl_4] by the visible light absorption spectrum (Fig. 1). B. Intramolecular oxidative coupling reactions: Oxidation of the type of compound 1 by a new oxidizing reagent was investigated. Oxidation of 1 (R_1=R_2=OCH_3); (R_1=OCH_3, R_2=H); and (R_1=R_2=H) gave the corresponding dienones 2 in yield 67%, 67%, and 39%, respectively. C. Intermolecular oxidative coupling reactions: Pummerer's ketone 3 from p-cresol, the dilactone 4 from ferulic acid and the unsymmetrical dimer 5 from methyl indole-3-acetate were obtained by the oxidation using a new oxidizing agent in yield 28%, 35% and 50%, respectively.
