DMSO as a Switchable Alkylating Agent in Heteroarene C-H Functionalization

Area of Science:

• Organic Chemistry
• Catalysis
• Heterocyclic Chemistry

Background:

• Direct C-H functionalization of heteroarenes is crucial for synthesizing complex molecules.
• Dimethyl sulfoxide (DMSO) is an abundant and inexpensive reagent, but its direct use as an alkylating agent in C-H functionalization is challenging.

Purpose of the Study:

• To develop a novel and efficient strategy for activating DMSO as a versatile alkylating agent.
• To achieve direct C-H methylation, trideuteromethylation, and methylthiomethylation of heteroarenes under mild conditions.

Main Methods:

• Utilized reagent-controlled photoredox catalysis.
• Employed visible light irradiation to activate DMSO.
• Investigated the functionalization of various heteroarene substrates.

Main Results:

• Demonstrated a novel strategy for DMSO activation in heteroarene C-H functionalization.
• Achieved a mild and direct switch between methylation/trideuteromethylation and methylthiomethylation.
• The reaction proceeds under simple and mild photoredox catalysis conditions.

Conclusions:

• The developed method provides a versatile and efficient route for heteroarene modification.
• The findings open new avenues for utilizing DMSO in synthetic organic chemistry.
• Mechanism was elucidated through experimental and computational studies.