Isolable C-Phosphonio-Boratavinyl Anion

Area of Science:

• Organometallic Chemistry
• Boron Chemistry
• Synthetic Chemistry

Background:

• Boron-containing compounds offer unique electronic properties.
• Stabilizing reactive intermediates is crucial in synthetic chemistry.
• Vinyl anions are important nucleophiles in organic synthesis.

Purpose of the Study:

• To synthesize and characterize a novel persistent C-phosphonio boratavinyl anion.
• To investigate the nucleophilic and basic properties of the synthesized anion.
• To explore its utility in stabilizing reactive intermediates and in synthetic transformations.

Main Methods:

• Synthesis of the C-phosphonio boratavinyl anion.
• Reactions with hydrogen (H2) and hexafluorobenzene (C6F6) to demonstrate reactivity.
• Reactions with electrophiles and carbon dioxide (CO2) to explore synthetic applications.

Main Results:

• Successful synthesis of a persistent C-phosphonio boratavinyl anion (1).
• The anion exhibits significantly higher negative charge on vinyl carbon (-1.59) compared to its carbon analogue (-0.76).
• Demonstrated strong nucleophilic and basic properties through rapid reactions with H2 and C6F6.
• Showcased its ability to stabilize reactive intermediates like halogenogermylenes.
• Achieved double insertion of CO2 into the B-C bond, forming a unique cyclic P-ylide (13).

Conclusions:

• The synthesized boratavinyl anion is a highly reactive species with significant nucleophilic and basic character.
• It serves as a valuable tool for introducing bulky, electron-donating substituents and stabilizing reactive intermediates.
• The reaction with CO2 highlights a novel pathway for forming unique cyclic structures.