Secondary Deuterium Isotope Effect in an Electrophilic Aromatic Substitution - Protodesilylation of Trimethylphenylsilane

✍ Scribed by Ivanka Szele

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: German
• Weight: 293 KB
• Volume: 64
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19810640833

✦ Synopsis

Abstract

Reaction rates for the protodesilylation of trimethylphenylsilane and of [2,4,6‐^2^H~3~]‐trimethylphenylsilane by HCIO~4~, were measured in aqueous methanol (2:5, v/v) and the secondary deuterium isotope effect for the reaction was found to be k~H~/k~D3~ = 0.79. The magnitude of the observed isotope effect supports a mechanism in which the rate‐determining step is the proton transfer from the hydronium ion to the silane to form a σ‐intermediate.