Carbamates: A Directing Group for Selective C-H Amidation and Alkylation under Cp*Co(III) Catalysis

Area of Science:

• Organic Chemistry
• Catalysis
• Asymmetric Synthesis

Background:

• Carbamates and thiocarbamates are versatile functional groups in organic synthesis.
• Developing efficient and selective catalytic methods for their transformations remains a key challenge.
• High-valent metal catalysis offers unique reactivity pathways.

Purpose of the Study:

• To report selective alkylation and amidation of carbamates and thiocarbamates using cobalt(III) catalysis.
• To explore the potential of this methodology for designing novel asymmetric catalysts.
• To demonstrate late-stage C-H functionalization of biologically relevant molecules.

Main Methods:

• Utilizing a stable, high-valent, cost-effective cobalt(III) catalyst.
• Investigating the reactivity of carbamates and thiocarbamates under catalytic conditions.
• Employing BINOL and SPINOL scaffolds for catalyst design.
• Performing mechanistic studies to elucidate the reaction pathway.

Main Results:

• Achieved selective alkylation and amidation of carbamates and thiocarbamates.
• Demonstrated the successful design of new asymmetric catalysts based on BINOL and SPINOL.
• Successfully performed late-stage C-H functionalization of l-tyrosine and estrone.
• Identified a base-assisted internal electrophilic substitution mechanism.

Conclusions:

• Cobalt(III) catalysis provides a powerful platform for selective carbamate and thiocarbamate functionalization.
• The developed methodology enables the synthesis of valuable chiral catalysts.
• This approach offers a new route for late-stage functionalization of complex organic molecules.