The Ionic Telomerization of Diene Compounds. IV. The Cationic Telomerization of Butadiene with Its Hydrobromides

Abstract The cationic telomerization of butadiene with its hydrobromides (1-bromo-2-butene and 3-bromo-1-butene) in the presence of metal halide was investigated. It was found that the molecular weights of the telomers depend on the conversion of the telomerization, initial bromide/ butadiene ratio and the solvent used. When halogenated hydrocarbons were used as solvents, telomers with high molecular weights and low unsaturations were obtained. On the other hand, the telomerizations in ether solvents gave telomers with low molecular weights, which contained appreciable amounts of the simple adducts of butadiene and bromobutene. The infrared spectra of the telomers suggested that the addition of butadiene occurred mainly at 1,4-position. On the basis of the analyses of the telomers, the reactivities of the carbonium ion to the basic species which were present in the reaction system were estimated.