Palladium(0)-Catalyzed Hydroalkoxylation of Hexafluoropropene: Synthesis of Hydrofluoroethers under Neutral Conditions

摘要

The development of alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) has become an important and urgent issue. Hydrofluoroethers (HFEs) are excellent candidates as environmentally friendly replacements for refrigerants, cleaning solvents, or blowing agents characterized by low ozone-depletion and global-warming effects.[1] HFEs (RFCHFCF2OR) can be synthesized regioselectively by the addition of an alcohol to an industrially available fluorinated alkene such as tetrafluoroethylene (TFE) or hexafluoropropene (HFP; 1) under strongly basic conditions.[2] However, the -fluorinated carbanion intermediates 5, formed by the addition of alkoxides to fluorinated alkene 1, lead to the production of unsaturated vinyl ethers 4 by -fluoride elimination (Scheme 1).[3]