Photocatalytic functionalizations of alkynes
Neha Chalotra1,2, Jaswant Kumar1,2, Tahira Naqvi3
1Academy of Scientific and Industrial Research (AcSIR), Ghaziabad 201002, India.
Visible light photoredox catalysis enables diverse alkyne functionalizations via single electron transfer (SET) radical generation. This review details methods for creating complex molecules, controlling selectivity, and future applications.
Area of Science:
- Organic Chemistry
- Photochemistry
- Catalysis
Background:
- Visible light photoredox catalysis has revolutionized organic synthesis.
- Alkynes are versatile building blocks but challenging to functionalize selectively.
- Single electron transfer (SET) is a key mechanism in photoredox reactions.
Purpose of the Study:
- To review visible light mediated functionalization reactions of alkynes.
- To highlight new mechanistic pathways and diverse structural transformations.
- To discuss advancements in stereoselective and regioselective control.
Main Methods:
- Utilizing visible light to mediate alkyne transformations.
- Employing photoredox catalysts for single electron transfer (SET).
- Developing various difunctionalization, annulation, cycloaddition, and oxidative reactions.
Main Results:
- Alkynes transformed into α-oxo compounds, β-keto sulfoxides, substituted olefins, N-heterocycles, internal alkynes, and sulfur-containing compounds.
- Successful control over stereoselectivity and regioselectivity in alkyne functionalization.
- Expansion of alkyne chemistry scope through novel radical pathways.
Conclusions:
- Visible light photoredox catalysis offers powerful strategies for alkyne functionalization.
- These methods enable the synthesis of valuable molecules for pharmaceutical and natural product chemistry.
- Future applications lie in further mechanistic exploration and synthetic utility.
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