Effects of Solvent and Residual Water on Enhancing the Reactivity of Six-Membered Silyloxyallyl Cations toward Nucleophilic Addition.

A new strategy for the generation of six-membered unsymmetrical silyloxyallyl cations using catalytic mild Brønsted acid is reported. These reactive intermediates were found to readily undergo direct nucleophilic addition with a broad range of nucleophiles to produce various α,α'-disubstituted silyl enol ether structural motifs. The findings also highlight the significance of the solvent effect and residual water in enhancing the reaction rate.