Perfluorinated enolates enolate reactivity

The nucleophilic reactivities of silyl enol ethers (58, R1 = alkyl) and silyl ketene acetals (58, R1 = 0-alkyl) have been measured for the triphenylsilyl (R2 = H5) substrate, and its perfluoro analogue (R2 = F5), using benzhydrylium cations as reference electrophiles.224 The triphenyl compound is 10 times less reactive than its trimethyl equivalent, but the perfluorination causes the C=C nucleophilicity to drop by 3-4 orders of magnitude. The new compounds have been placed on scales of nucleophilicity taken from the literature. 

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