We report the first successful allylation of aromatic esters by allyltrimethylsilane. The reaction is mediated by 0.3-1.0equiv. of titanium tetrachloride (TiCl4) at room temperature and leads in a multi-step, one-pot reaction to quaternary triallylmethane derivatives 5. The most efficient ester possessed two ortho-methoxy substituents on the phenol ring. Molecular modelling revealed the ability of this compound to form a bidentate titanium complex, thus improving the steric accessibility of the ester carbonyl to nucleophilic attack.
- Lewis acids