CuO nanoparticle-catalyzed tandem reactions for the synthesis of robust polybenzoxazole.

We report the synthesis of CuO nanoparticles (NPs) by controlled oxidation of Cu NPs and the study of these NPs as a robust catalyst for ammonia borane dehydrogenation, nitroarene hydrogenation, and amine/aldehyde condensation into Schiff-base compounds. Upon investigation of the size-dependent catalysis for ammonia borane dehydrogenation and nitroarene hydrogenation using 8-18 nm CuO NPs, we found 13 nm CuO NPs to be especially active with quantitative conversion of nitro groups to amines. The 13 nm CuO NPs also efficiently catalyze tandem reactions of ammonia borane, diisopropoxy-dinitrobenzene, and terephthalaldehyde, leading to a controlled polymerization and the facile synthesis of polybenzoxazole (PBO).