Treatment of alkyl halides, including secondary and tertiary alkyl bromides, with allylic Grignard reagents in the presence of a catalytic amount of copper(II) triflate in diisopropyl ether at 25 degrees C yielded the corresponding allylated products in high yields. The coupling reactions of tertiary alkyl halides lead to construction of allylated quaternary carbon centers. The active species is likely to be allylcuprate.