Intramolecular nucleophilic addition to unsaturated carbon. Dependence of cyclization efficiency on the method of carbon-carbon bond cleavage utilized to generate the reactive species
Styrenes were alkylated with alkyl tosylates, sulfates and bromides in the presence of a zirconocene catalyst and nBuMgCl in THF. By the use of this reaction, primary and secondary alkylgroups can be introduced regioselectively at the benzylic carbon of styrenes to give α-substituted ethylbenzenes.