Photoinduced TBADT-Catalyzed Alkylation of Alkyl ( <i>E</i> )-3-(2-Methacrylamidoaryl)acrylates to Access 3,4-Dihydroquinolin-2-(1 <i>H</i> )-ones

Herein, we present a sustainable photochemical approach for the synthesis of 3,4-dihydroquinolin-2-(1<i>H</i>)-ones via TBADT (hydrogen-atom transfer) catalyst-mediated radical cascade cyclization of alkyl (<i>E</i>)-3-(2-methacrylamidoaryl)acrylates with cycloalkanes. Significantly, the products were obtained with a high <i>syn</i> stereoselectivity between the ester group and the incoming radical source. This strategy enables the diversification of functionalized alkyl (<i>E</i>)-3-(2-methacrylamidoaryl)acrylate with a drug. This transformation operates under mild reaction conditions and enables dual C-C bond formation. Notably, scale-up reactions and mechanistic investigations were performed.