Directed, Remote Dirhodium C(sp³)-H Functionalization, Desaturative Annulation, and Desaturation.

Area of Science:

• Organometallic Chemistry
• Catalysis
• Organic Synthesis

Background:

• Iminodirhodium intermediates are underexplored reactive species.
• Traditional methods for C-H functionalization and desaturation have limitations.

Purpose of the Study:

• To explore the reactivity of iminodirhodium intermediates generated in situ.
• To develop novel catalytic transformations including C-H functionalization, desaturative annulation, and directed desaturation.

Main Methods:

• Generation of iminodirhodium intermediates from O-tosyloximes using Rh2(esp)2.
• Utilizing these intermediates for C-H functionalization with diverse nucleophiles.
• Employing intermediates for desaturative annulation and directed desaturation reactions.

Main Results:

• Achieved remote C-H functionalizations with a broad range of nucleophiles, including ethers and acyl silanes.
• Demonstrated a biomimetic 1,3-methylene C-C ring-closure (desaturative annulation) with loss of two hydrogens.
• Developed regioselective methods for creating gamma,delta- or gamma,delta,epsilon,zeta-olefins via directed desaturation.
• Showcased reactivity across various C(sp3)-H centers like benzylic, allylic, and tertiary positions.

Conclusions:

• Iminodirhodium intermediates offer a versatile platform for challenging organic transformations.
• These methods provide new avenues for regioselective synthesis and C-H functionalization.
• The broad substrate scope and unique reaction modalities highlight the transformative potential of these intermediates.