A novel direct synthesis of 3-acyl-4-aryldihydroquinolin-2(1H)-ones via metal-free radical tandem cyclization between N-arylcinnamamides and aldehydes

An efficient metal-free and practical method for the synthesis of disubstituted dihydroquinolin-2(1H)-ones via intermolecular radical tandem addition/cyclization was developed. This method provides a novel and straightforward route to 3-acyl-4-aryldihydroquinolin-2(1H)-ones in one step by C-H functionalization. A possible mechanism for the formation of 3,4-dihydroquinolin-2(1H)-ones is also proposed.