Copper-catalyzed dehydrogenative cyclization/alkenylation towards dihydroquinolinones

Area of Science:

• Organic Chemistry
• Catalysis
• Materials Science

Background:

• Dihydroquinolinones are important heterocyclic scaffolds with diverse biological activities.
• Efficient synthetic methodologies are crucial for accessing functionalized dihydroquinolinone derivatives.
• Copper catalysis offers a versatile platform for C-H functionalization and cyclization reactions.

Purpose of the Study:

• To develop an efficient copper-catalyzed one-pot sequential synthesis of alkenylated quinolinyl dihydroquinolinones.
• To explore the utility of readily available starting materials like ketones, 1,3-cyclohexanediones, and benzyl alcohols.
• To investigate the photophysical properties of the synthesized compounds.

Main Methods:

• Copper-catalyzed dehydrogenative cyclization of ketones and 1,3-cyclohexanediones.
• Subsequent alkenylation using benzyl alcohols in a one-pot sequential manner.
• Reaction monitoring via 1H NMR and control experiments to elucidate the reaction mechanism.

Main Results:

• Successful synthesis of a range of alkenylated quinolinyl dihydroquinolinones in high yields.
• The reaction proceeds under mild and environmentally friendly conditions.
• Scalable synthesis demonstrated without significant side product formation.
• Synthesized compounds exhibit diverse absorption and emission spectra.
• Compound 4F displays notable acidochromic properties.

Conclusions:

• A straightforward and efficient copper-catalyzed one-pot method for synthesizing alkenylated quinolinyl dihydroquinolinones has been established.
• The developed methodology is mild, environmentally friendly, and scalable.
• The synthesized compounds possess interesting photophysical characteristics, with potential applications in sensing due to acidochromism.