Incorporation of radiohalogens via versatile organometallic reactions: applications in radiopharmaceutical chemistry

Factors that must be considered for the design of radiohalogenated radiopharmaceuticals include the stability and availability of the substrate, the physical half-life of the radiohalogen and the in vivo stability of the radiolabel. Vinyl and phenyl radiohalogen bonds show more in vivo stability than the alkyl radiohalogen bonds. Consequently, a variety of methods suitable for the synthesis of tissue specific radiopharmaceuticals bearing a vinyl or phenyl radiohalogen have been developed involving the synthesis and halogenation of metallovinyl and phenyl intermediates. The halogens and metallation reactions include iodine and bromine and alanation, boronation, mercuration, stannylation, and thallation, respectively. 19 refs.; 2 figs.; 7 schemes; 1 table