Reaction of Perfluoroalkyl Iodides with Electron-Deficient Olefins under UV Irradiation

Article abstract of DOI:10.1021/jo00116a038

The reaction of perfluoroalkyl iodides 1 with acrylates, acrylic acid, acrylamide, and acrylonitrile has been investigated.In the presence of a catalytic amount of palladium(0), the reaction of R_f with ethyl acrylate produces mostly polymer.Under irradiation with 254 nm UV light, perfluoroalkyl iodides react with ethyl acrylate to give high yields of the 1:1 addition products (74-88percent isolated yield, CnF(2n+1)CH2CHICO2Et) and small amounts of 1:2 adducts (<10percent NMR yield) at ambient temperature.The functionalized iodide 5-iodo-3-oxaoctafluoropentanesulfonyl fluoride also reacts with ethyl acrylate to give the 1:1 adduct in 88percent yield.However, it has been found that the reaction selectivity is related to the length of the perfluoroalkyl group in 1 when methyl acrylate is employed in the reaction under similar conditions.Both 1:1 (56-76percent) and 1:2 adducts are formed when methyl acrylate reacts with short-chain perfluoroalkyl iodides , whereas the reaction of perfluorohexyl or longer chain perfluoroalkyl iodides /= 6> gives predominantly the 1:1 addition products (>85percent).The formation of the 1:2 adduct can be efficiently suppressed by using excess R_fI in the reaction.The reaction of N,N-dimethylacrylamide with perfluoropropyl iodide (1a) produces exclusively the 1:1 adduct.Products from the further elimination, reduction, and decarboxylation of the 1:1 and 1:2 adducts are observed when 1a reacts with methyl methacrylate under similar conditions.The reaction of 1a with acrylonitrile produces the 1:1 and 1:2 adducts in 53percent and 74percent yields, respectively.An addition-reduction product, n-C3H7CH2CH2CO2H (68percent), is obtained in the reaction of acrylic acid with 1a.