Versatile Access to Martin’s Spirosilanes and Their Hypervalent Derivatives

A new route to Martin’s spirosilanes
has been devised. The
original synthesis does not allow diversely substituted spirosilane
derivatives to be synthesized, and thus their corresponding silicates.
In this report, Martin’s spirosilanes bearing alkyl, aryl,
halogen, alkoxy, and trifluoromethyl substituents on the aryl ring
have been prepared through a versatile four-step route. Addition of
fluoride onto these Lewis acids as a prototypical reaction with a
nucleophile yielded a library of stable fluorosilicates. Both sets
of compounds have been characterized by X-ray crystallography.