Single-carbon-atom transfer to para-quinone methides from TMSCF₂Br

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Fluorine Chemistry

Background:

• Single-carbon atom transfer reactions are crucial for building complex molecules.
• Limited availability of atomic carbon sources has restricted progress in this area.

Purpose of the Study:

• To develop a novel single-carbon atom transfer reaction using a readily available precursor.
• To demonstrate the synthesis of gem-difluorinated spirocyclic compounds and their subsequent transformations.

Main Methods:

• Utilized TMSCF2Br as an atomic carbon equivalent.
• Employed a cascade of 1,6-addition and TBAF-catalyzed intramolecular cyclization with para-quinone methides (p-QMs).
• Investigated stereoselective nucleophilic capture and nucleophilic vinylic substitution (SNV) reactions.

Main Results:

• Efficient formation of gem-difluorinated spiro[2.5]octa-4,7-dien-6-ones.
• Stereoselective synthesis of fluorinated alkenes with high stereocontrol.
• Construction of tetrasubstituted alkenes and cyclic 2-methylene-2,3-dihydrofurans via SNV reactions.

Conclusions:

• TMSCF2Br serves as a practical atomic carbon equivalent for complex molecule synthesis.
• The developed method provides access to valuable fluorinated building blocks.
• The reaction pathway offers a versatile platform for stereoselective synthesis of diverse organic structures.