Catalytic Enantioselective Dihalogenation in Total Synthesis

Area of Science:

• Organic Chemistry
• Natural Product Synthesis
• Halogen Chemistry

Background:

• Over 5000 biogenic halogenated molecules are known, with increasing discovery in marine environments.
• Naturally occurring organohalogens are structurally diverse and exhibit significant biological activities.
• Enantioselective methods for creating carbon-halogen bonds are scarce, hindering natural product synthesis.

Purpose of the Study:

• To develop a catalytic enantioselective dihalogenation reaction for synthesizing organohalogens.
• To apply this method to the total synthesis of various halogenated natural products.
• To establish a framework for synthesizing chiral organohalogens using catalytic enantioselective dihalogenation.

Main Methods:

• Development of a TADDOL-mediated dibromination of cinnamyl alcohols.
• Extension to a second-generation system for selective bromochlorination, dichlorination, and dibromination.
• Application of catalytic enantioselective dihalogenation in the synthesis of natural products.

Main Results:

• Successful synthesis of chiral vicinal bromochlorides, including (+)-halomon.
• Enantioselective dichlorination provided access to chlorosulfolipids.
• Synthesis of chiral monohalides via solvolysis of enantioenriched bromochlorides, leading to bromocyclohexane natural products.

Conclusions:

• The developed catalytic enantioselective dihalogenation method is highly effective for synthesizing diverse halogenated natural products.
• This methodology provides efficient access to chiral organohalogens, addressing a significant gap in synthetic chemistry.
• The study highlights the importance of developing new halogenation methodologies for natural product synthesis.