Isoxazole group directed Rh(III)-catalyzed alkynylation using TIPS-EBX.

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• C-H functionalization is a key strategy in organic synthesis.
• Isoxazoles are important heterocyclic compounds with diverse applications.
• Developing efficient methods for C-H alkynylation of heterocycles remains a challenge.

Purpose of the Study:

• To develop a novel rhodium(III)-catalyzed C-H alkynylation of isoxazoles.
• To explore the scope and limitations of the developed synthetic method.
• To investigate the reaction mechanism.

Main Methods:

• Rhodium(III)-catalyzed direct alkynylation reaction.
• Utilized a hypervalent iodine reagent (TIPS-EBX) for alkynylation.
• Employed isoxazoles as directing group substrates.

Main Results:

• Achieved highly effective isoxazole-directed ortho C-H alkynylation.
• Demonstrated direct di- and mono-alkynylation.
• Reaction showed a wide substrate scope and proceeded under benign conditions.

Conclusions:

• A novel and effective rhodium(III)-catalyzed C-H alkynylation of isoxazoles has been established.
• The method offers a valuable tool for synthesizing functionalized isoxazoles.
• Preliminary mechanistic studies suggest a chelation-assisted pathway.