Modular Dual-Tasked C-H Methylation via the Catellani Strategy

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Methylation is crucial for synthesizing functionalized organic molecules.
• Existing methylation methods often require harsh conditions or expensive reagents.
• Developing efficient and versatile methylation strategies remains an active area of research.

Purpose of the Study:

• To develop a novel dual-tasked methylation strategy.
• To create a versatile toolbox for preparing diversified methylated arenes.
• To enable late-stage methylation with high functional group tolerance and stereoretention.

Main Methods:

• Cooperative palladium/norbornene catalysis for dual-tasked methylation.
• Utilizing readily available (hetero)aryl halides and inexpensive methylating reagents (MeOTs, trimethylphosphate).
• Coupling of "ipso" terminations with "ortho" C-H methylation.

Main Results:

• Successful synthesis of diversified methylated arenes.
• Demonstrated scalability and excellent functional group tolerance.
• Application to isotope-labeled methylation (CD3OTs, 13CH3OTs) and late-stage modification of biorelevant substrates with complete stereoretention.

Conclusions:

• The developed dual-tasked methylation toolbox is versatile, efficient, and practical.
• It offers inexpensive methyl sources and simple reaction procedures.
• The methodology is suitable for both academic and industrial research, including late-stage functionalization.