Direct cupration of fluoroform.

Area of Science:

• Organometallic Chemistry
• Synthetic Organic Chemistry
• Fluorine Chemistry

Background:

• The trifluoromethyl (CF3) group is crucial for modifying the properties of organic molecules.
• Fluoroform (CF3H) is an attractive but challenging source for CF3 group introduction.
• Direct C-H functionalization methods are highly sought after in modern synthesis.

Purpose of the Study:

• To establish the first direct cupration reaction using fluoroform.
• To develop novel copper trifluoromethyl (CuCF3) reagents.
• To demonstrate the utility of these reagents in trifluoromethylation reactions.

Main Methods:

• Treatment of copper(I) halides (CuX) with alkali metal alkoxides (MOR) in polar aprotic solvents (DMF, NMP).
• Reaction of in-situ generated alkoxycuprates with fluoroform (CF3H) at room temperature and atmospheric pressure.
• Stabilization of the resulting CuCF3 solutions using HF sources.
• Structural characterization of novel copper complexes.

Main Results:

• Successful direct cupration of fluoroform was achieved, yielding CuCF3 derivatives.
• The CuCl/t-BuOK system provided the best results, with nearly quantitative yields in seconds.
• The reaction mechanism was shown to be highly selective, not involving CF3- or CF2 intermediates.
• Stabilized CuCF3 reagents effectively trifluoromethylated various organic and inorganic electrophiles without additional ligands.
• Several novel Cu(I) complexes were synthesized and structurally characterized.

Conclusions:

• A novel and efficient method for synthesizing copper trifluoromethyl reagents directly from fluoroform has been developed.
• The developed CuCF3 reagents are stable and versatile for trifluoromethylation of diverse substrates.
• This work provides a significant advancement in accessing trifluoromethylated compounds using readily available fluoroform.