Physical properties
mp 141–142 °C;1,2 a somewhat higher value
(143–145 °C) is cited in the Aldrich catalog.
Uses
Tribenzylchlorosilane is widely used as reagent for alcohol protection.
Preparation
It is prepared by reaction of benzylmagnesium
chloride with SiCl4 in ether; separation from mono- and
dibenzylated chlorosilane byproducts is then accomplished by
fractional distillation (boiling range 300–360 °C/100 mmHg).
Other preparations involve the chlorination of tribenzylsilane
using Cl2
or an acyl chloride. No yields are reported for any
of the above preparative procedures.
Purification Methods
It is recrystallised three times from pet ether (in slender colourless needles, m 141o). It is sparingly soluble in pet ether but is soluble in Et2O. It does not fume in moist air but is decomposed by H2O to give tribenzyl silanol m 106o (from pet ether). [Robinson & Kipping J Chem Soc 93 439 1908, Jenkins & Post J Org Chem 15 556 1950, Beilstein 16 H 906, 16 IV 1498.]
