Pd-catalyzed oxidative coupling of 2-aroylimidazoles with benzyl alcohols: Access to imidazole functionalized phthalazines and phthalazin-1(2H)-ones

The palladium-catalyzed direct oxidative coupling reaction between 2-aroylimidazoles with aromatic aldehydes or benzyl alcohols under oxidation conditions has been achieved to furnish a variety of carbonyl functionalized 2-aroylimidazoles in moderate to good yields. The obtained products could be selectively transformed to the corresponding phthalazines and phthalazin-1(2H)-ones with hydrazine hydrate as the cyclization partner under different reaction temperature and construct an array of structurally diverse nitrogen-containing heterocycles.