152879-06-6Relevant articles and documents
The Yukawa-Tsuno relationship for the β-silicon effect in the solvolysis rates of 2-(aryldimethylsilyl)ethyl chlorides
Fujio, Mizue,Uchida, Mai,Okada, Ayumi,Alam, Md. Ashadul,Fujiyama, Ryoji,Siehl, Hans-Ullrich,Tsuno, Yuho
, p. 1834 - 1842 (2007/10/03)
Solvolysis rates of 2-(aryldimethylsilyl)ethyl chlorides were determined conductimetrically in 60% (v/v) aqueous ethanol. The effects of aryl substituents at the silyl atom on the solvolysis rates at 50°C were correlated with essentially nonresonant σ parameters of r = 0:10 in terms of Yukawa-Tsuno (Y-T) Eq. 1, giving a ρ value of -1:75. Such a high ρ value may be regarded as the effect of aryl ring on the bridged Si in the rate-determining step. The Si-bridging is consistent with the fact that the solvolysis of the unsubstituted substrate with d2-labeled ethylene moiety gave substitution products with label scrambling. The arylsilyl substituent effects were likewise analyzed for several relevant sets of β-silyl systems in order to ascertain significant variations of ρ values from system to system; Y-T Eq. 1 correlated quite excellently with essentially nonresonant sigmas of negligible resonance demand (r ? 0:10), to exhibit significant variations of ρ from -1:75 to -0:95.
