Synthesis and characterisation of new silicon–perfluoropropenyl compounds

Novel, stable silicon–pentafluoropropane compounds have been synthesised from the direct reaction of hydrofluorocarbons Z-CFH[double bond, length as m-dash]CFCF(3) (Z-HFC-1225ye) with (n)BuLi, followed by appropriate silicon-halide. The compounds have been characterized by multinuclear NMR studies ((19)F, (1)H, (29)Si and (13)C), DFT studies and structural confirmation was obtained by X-ray diffraction. Based on the outcome of treating synthetic silicon–pentafluoropropene compounds with different nucleophilic sources ((n)BuLi, (t)BuLi, MeLi, and PhLi) and computed for this reaction DFT energetics, it is clear that the C–F(trans) bond is more active than C–F(gem) (F(gem) and F(trans) are labelled with respect to Si). This provides a route for efficient modification of pentafluoropropene group, that can be a crucial step in developing pharmaceuticals that include propenyl or vinyl groups, addressing the demand for medicines based on long carbonic chains.