Regiochemistry in the hydroboration of allylsilanes
作者:Ian Fleming、Nicholas J. Lawrence
DOI:10.1016/s0040-4039(00)87838-7
日期:——
The hydroboration of most types of allylsilane is highly selective for the formation of the product having the silicon and boron in a 1,3 relationship when the hydroboratingagent is 9-BBN. There is only a low degree of correlation between the difference in the chemical shifts of the trigonal carbon atoms on an alkene and the regioselectivity in hydroboration with either borane:THF or 9-BBN.
2‐(aryldimethylsilyl)‐1‐tert‐butylethyl trifluoroacetates were determined conductimetrically in 60% (v/v) aqueous ethanol. The effects of aryl substituents at the silicon atom on the solvolysis rates at 50 °C were correlated with parameters of r+ = 0.15 with the Yukawa–Tsuno equation, giving ρ values of −1.5 for both secondary α‐Me and α‐tert‐Bu systems. The ρ values for those secondary systems are less negative than