Visible-light-promoted oxidative halogenation of alkynes

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Catalysis

Background:

• Halogenation, particularly geminal dihalogenation, enhances the biological activity of natural compounds.
• Natural halogenated molecules exhibit diverse therapeutic potential, driving the need for advanced synthetic methods.
• Current synthetic strategies for halogenated compounds often lack efficiency and diversity.

Purpose of the Study:

• To develop a novel, catalyst-free oxidative halogenation method.
• To establish an efficient and compatible late-stage transformation for synthesizing dihaloacetophenones (DHAPs).
• To facilitate drug discovery by providing access to valuable halogenated scaffolds.

Main Methods:

• Catalyst-free oxidative halogenation under ambient conditions (air, water, visible light, room temperature).
• Utilizing phenylacetylene as both a reactant and a catalyst to shuttle electron transfer.
• Employing simple conjugated molecules to facilitate the reaction between oxygen and halide ions.

Main Results:

• Successful synthesis of dihaloacetophenones (DHAPs) via a novel oxidative halogenation pathway.
• Demonstration of a highly compatible late-stage functionalization strategy.
• Achieved halogenation under environmentally benign and accessible conditions.

Conclusions:

• The developed method offers an efficient, catalyst-free route to DHAPs.
• This approach is suitable for late-stage functionalization in drug discovery programs.
• Ambient condition synthesis represents a significant advancement in halogenation chemistry.