A FACILE PERFLUOROALLYLATION OF OLEFINS

The addition of F-allyl iodide to terminal alkenes is induced by a cat alytic amount of copper powder in the absence of solvent at room tempe rature to 50 degrees C to give the corresponding 1:1 adducts in good y ields. A variety of functional groups such as trimethylsilyl, alkyl, e poxy, ester, hydroxyl, bromo, ether, and phosphonate are tolerated in the addition reaction. This reaction also worked well with internal ol efins such as cyclohexene, cyclopentene, and 4-octene. Reaction with d ienes gives the corresponding linear adduct and cyclization adduct dep ending on the chain length of the dienes. With 1,7-octadiene, a bis(pe rfluoroallyl) product is formed, while a tetrahydrofuran derivative is obtained with diallyl ether. Reduction of the adducts with zinc in th e presence of nickel dichloride in moist THF or zinc in moist DMF affo rds the perfluoroallyl derivatives. The adduct reacts with zinc in DMF to form a zinc reagent which couples with organic electrophiles in th e presence of CuBr.