Photochemistry of 5- and 6-Iodouracils in the Presence of Allylsilanes and Alkenes. A Convenient Route to C5- and C6-Substituted Uracils

Article abstract of DOI:10.1021/jo00376a018

The photocoupling reaction of 5- and 6-iodouracil derivatives with allylsilanes and alkenes is presented.Irradiation of 5-iodouridine (5) and 5-iodo-2'-deoxyuridine (6) in the presence of allyltrimethylsilane in aqueous acetonitrile gave 5-allyluridine (7) and 5-allyl-2'-deoxyuridine, respectively.Irradiation of 6-iodo-1,3-dimethyluracil (11) in the presence of allylsilanes and alkyl-substituted olefins produced the corresponding C6-substituted uracil derivatives in good yields. 5-Fluoro-6-iodo-1,3-dimethyluracil (12) underwent a similar photocoupling reaction with allylsilanes and alkenes.The photocoupling reaction provides a convenient method for carbon-carbon bond formation at the C5 or C6 position of uracil derivatives.A radical addition mechanism has been proposed for this novel photocoupling reaction.