Three Component syn-1,2-Arylmethylation of Internal Alkynes.

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Developing efficient methods for constructing substituted olefins is crucial in organic synthesis.
• Palladium-catalyzed cross-coupling reactions have revolutionized the synthesis of carbon-carbon bonds.

Purpose of the Study:

• To develop a novel three-component syn-1,2-arylmethylation of internal alkynes.
• To explore the late-stage functionalization of biologically relevant motifs using this new methodology.

Main Methods:

• Utilized a palladium catalyst for the coupling of iodo-arenes, methyl boronic acid, and internal alkynes (ynamides, yne-acetates, alkynes).
• Investigated the reaction scope, functional group tolerance, regioselectivity, and stereoselectivity.
• Applied the method to late-stage functionalization of biologically relevant motifs and explored various methylation strategies.

Main Results:

• Successfully synthesized methyl-containing tetra-substituted olefins with high regio- and stereoselectivity.
• Demonstrated broad substrate scope and excellent functional group tolerance.
• Achieved late-stage syn-1,2-arylmethylation of alkynes and ynamides, including aryl-alkylation and aryl-trideuteriomethylation.
• Transformed the resulting alkenes into valuable β-amino-indenones and α-fluoro-α'-methyl ketones.

Conclusions:

• The developed Pd-catalyzed three-component reaction provides an efficient and versatile route to methyl-substituted olefins.
• The methodology is applicable to late-stage functionalization and the synthesis of complex organic molecules.
• This work expands the synthetic utility of alkynes and offers new pathways to important chemical scaffolds.