Hypervalent Fluoro-iodane-Triggered Semipinacol Rearrangements: Synthesis of α-Fluoro Ketones.

Area of Science:

• Organic Chemistry
• Fluorination Chemistry
• Synthetic Methodology

Background:

• Hypervalent fluoro-λ³-iodanes are recognized for their utility in selective fluorination under mild conditions.
• Accessing molecules with tertiary C,F-carbon centers adjacent to ketone groups remains a synthetic challenge.
• Existing fluorination methods often lack the efficiency and selectivity required for complex structural motifs.

Purpose of the Study:

• To develop a novel cascade reaction involving semipinacol rearrangement and fluorination using hypervalent fluoro-λ³-iodanes.
• To synthesize cyclopentanone derivatives featuring tertiary C,F-carbon centers.
• To explore the feasibility of enantioselective transformations within this reaction system.

Main Methods:

• Reaction of styrene derivatives with hypervalent fluoro-λ³-iodanes.
• Induction of a cascade process combining semipinacol rearrangement, fluorination, and aryl migration.
• Characterization of the resulting fluorinated cyclopentanone products.

Main Results:

• Successful synthesis of various cyclopentanones bearing adjacent tertiary C,F-carbon centers and ketone groups.
• Achieved yields up to 96% for the target fluorinated compounds.
• Demonstrated preliminary success in enantioselective variants, indicating potential for asymmetric synthesis.

Conclusions:

• The developed cascade reaction provides an efficient route to valuable fluorinated cyclopentanone scaffolds.
• This methodology overcomes limitations of previous methods for constructing tertiary C,F-carbon centers.
• The reaction's adaptability to asymmetric synthesis opens avenues for chiral fluorinated molecule development.