Activation of C-F Bonds by Electrophilic Organosilicon Sites Supported on Sulfated Zirconia.

The reaction of allyltriisopropylsilane with partially dehydroxylated sulfated zirconium oxide (SZO) forms surface organosilicon species. Solid-state NMR studies of the organosilicon functionalized SZO shows that electrophilic [TIPS][SZO] sites are present on the surface, in addition to less reactive TIPS-Ox and SiOx species. The electrophilic [TIPS][SZO] sites are strong Lewis acids from solid-state 31 P NMR analysis of triethylphosphine oxide (O=PEt3 ) contacted materials. [TIPS][SZO] is active in hydrodefluorination reactions in the presence of Et3 SiH.