A Benign Lewis Acid Catalyzed Approach for Mannich Reaction: Straight Forward Synthesis of β-Amino Ketones using Simple Iron Salts as Catalyst

In this approach, FeCl3 was used as a moderate Lewis acid and an efficient catalyst to synthesize β-amino ketones via three-component Mannich reaction between series of substituted aromatic aldehyde, aryl amine and aryl ketones under mild conditions, where the Lewis acidic FeCl3 facilitates both C-C and C-N bond formation simultaneously without any complicated catalyst preparations. An inexpensive, readily accessible FeCl3 as an Lewis acid catalyst for synthesizing β-amino ketones through a straightforward tandem reaction in a one-pot protocol is unveiled with benefits like a short reaction time, rapid workup and good to outstanding yields under more eco-friendly conditions. This mild Lewis catalyst provides a sustainable and alternative method for obtaining synthetically necessary β-amino ketones under greener conditions. The present methodology opens the new doors for synthesizing substituted β-amino ketones and their chemical structures were verified by 1H and 13C NMR spectroscopic data. 1,3-Diphenyl-3-(phenylamino)propan-1-one (4a) was evaluated for antibacterial, antifungal, antioxidant and anticancer activities.