The Catalytic Asymmetric Intermolecular Prins Reaction

Area of Science:

• Organic Chemistry
• Catalysis
• Asymmetric Synthesis

Background:

• Catalytic asymmetric reactions of olefins with formaldehyde are limited.
• Metal-free approaches for these transformations are largely undisclosed.
• 1,3-dioxanes and 1,3-diols are valuable synthetic intermediates.

Purpose of the Study:

• To develop a novel metal-free catalytic asymmetric intermolecular Prins reaction.
• To synthesize enantioenriched 1,3-dioxanes using styrenes and paraformaldehyde.
• To explore the reaction mechanism and the utility of the products.

Main Methods:

• Enantioselective intermolecular Prins reaction using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts.
• Utilized styrenes and paraformaldehyde as substrates.
• Employed isotope labeling experiments and computational studies for mechanistic investigation.

Main Results:

• Successfully synthesized enantioenriched 1,3-dioxanes via a metal-free catalytic asymmetric Prins reaction.
• Mechanistic studies suggest a concerted, highly asynchronous addition pathway.
• Demonstrated the transformation of 1,3-dioxanes into valuable optically active 1,3-diols.

Conclusions:

• Developed a rare and novel metal-free catalytic asymmetric Prins reaction.
• The confined iIDP Brønsted acid catalysts enable efficient enantioselective synthesis.
• The resulting chiral 1,3-dioxanes are versatile precursors for optically active 1,3-diols.