Hydrofluorocarbon 245fa: a versatile new synthon in alkyne chemistry

Area of Science:

• Organic Synthesis
• Organometallic Chemistry
• Fluorine Chemistry

Background:

• Chlorofluorocarbons (CFCs) are being phased out due to environmental concerns.
• Development of alternative reagents for synthesizing fluorinated organic compounds is crucial.
• Trifluoropropynyl groups are valuable building blocks in medicinal chemistry and materials science.

Purpose of the Study:

• To establish 1,1,1,3,3-pentafluoropropane (HFC 245 fa) as a convenient precursor for trifluoropropynyllithium.
• To demonstrate a one-pot procedure for synthesizing novel and known trifluoropropynyl-containing systems.
• To explore mild reaction conditions for generating and utilizing trifluoropropynyllithium.

Main Methods:

• Reaction of 1,1,1,3,3-pentafluoropropane (HFC 245 fa) with a suitable base to generate trifluoropropynyllithium.
• In situ trapping of the generated trifluoropropynyllithium with various electrophiles.
• One-pot synthesis strategy to minimize purification steps and improve efficiency.

Main Results:

• 1,1,1,3,3-pentafluoropropane (HFC 245 fa) serves as an effective and convenient source of trifluoropropynyllithium.
• A range of novel and known trifluoropropynyl-containing compounds were successfully synthesized.
• The procedure was conducted under mild reaction conditions, indicating high functional group tolerance.

Conclusions:

• 1,1,1,3,3-pentafluoropropane (HFC 245 fa) offers a practical and accessible route to trifluoropropynyllithium.
• The developed one-pot method provides an efficient strategy for accessing diverse trifluoropropynyl derivatives.
• This methodology holds promise for the streamlined synthesis of fluorinated molecules in various chemical applications.