Search

Aromatic azo compounds, which play an important role in pharmaceutical and industrial applications, still face great challenges in synthesis. Herein, we report a molybdenum oxide compound, [N(C4H9)4]2[Mo6O19] (1), catalyzed selective oxidation of anilines with hydrogen peroxide as green oxidant. The oxidation of anilines can be realized in a fully selectively fashion to afford various symmetric/asymmetric azobenzene and azoxybenzene compounds, respectively, by changing additive and solvent, avoiding the use of stoichiometric metal oxidants. Preliminary mechanistic investigations suggest the intermediacy of highly active reactive and elusive Mo imido complexes. [ABSTRACT FROM AUTHOR]

The first example of a heterogeneous iron(III)-catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram-scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale. [ABSTRACT FROM AUTHOR]