Lewis Acid Catalyst Free Electrophilic Alkylation of Silicon-Capped π Donors in 1,1,1,3,3,3-Hexafluoro-2-propanol

摘要

The electrophilic alkylation of n donors most often implies the use of Lewis acid catalysts for the generation of reactive electrophilic species from covalent precursors. A promising alternative to this procedure has recently been suggested in studies by Mayr and co-workers. In particular, it was disclosed that cationic intermediates generated by solvolysis of S_N1-active substrates in polar solvents, such as acetone/ water, acetonitrile/water, 2,2,2-trifluoroethanol (TFE), or 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), can be trapped by π nucleophiles (activated arenes, heteroarenes, or enol ethers) provided the nucleophilicity of the latter is higher than that of the solvent system.