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.