Copper-catalyzed dehydrogenative cyclization/alkenylation towards dihydroquinolinones

An efficient copper-catalyzed one-pot sequential synthesis of alkenylated quinolinyl dihydroquinolinones is reported, utilizing ketones, 1,3-cyclohexanediones, and benzyl alcohols via dehydrogenative cyclization, followed by alkenylation. This highly straightforward method provides a mild and environmentally friendly approach, and scalable reactions are carried out without generating side products. Furthermore, a plausible reaction mechanism is proposed based on control-experiment studies and reaction monitoring via1H NMR analysis. In addition, the photophysical behavior of the synthesized products showed various responses in the absorption and emission spectra. Upon further examination, compound 4F was found to have acidochromic properties, leading to noticeable colour changes. A mild and one-pot sequential route to access diversely substituted quinolinyl dihydroquinolinones has been proposed, using a dehydrogenative cyclization/alkenylation strategy with good yields.