Reaction of [NEt4]2[ReBr3(CO)3] with 2,4-pentanedione (acac) yields a complex of the type fac-Re(acac)(OH2)(CO)3 (1) under aqueous conditions. 1 was further reacted with a monodentate ligand (pyridine) to yield a fac-Re(acac)(pyridine)(CO)3 complex (2). Complex 1 was found to react with primary amines to generate a Schiff base (imine) in aqueous solutions. When a mixed-nitrogen donor bidentate ligand, 2-(2-aminoethyl)pyridine, that has different coordination affinities for fac-Re(acac)(OH2)(CO)3 was utilized, a unique tridentate ligand was formed in situ utilizing a metal-assisted Schiff base formation to yield a complex fac-Re(CO)3(3[(2-phenylethyl)imino]-2-pentanone) (3). Tridentate ligand formation was found to occur only with the Re-coordinated acac ligand. Reactions of acac with fac-Re(CO)3Br(2-(2-aminoethyl)pyridine) (4) or a mixture of [NEt4]2[ReBr3(CO)3], acac, and 2-(2-aminoethyl)pyridine did not yield the formation of complex 3 in water.
Androgen receptors are overexpressed in most primary and metastatic prostate cancers. A series of single photon emission computed tomography imaging agents (SPECT) utilizing the organometallic radioactive imaging species, fac-99mTc(OH(2))(3)(CO)(3)+, were prepared on the basis of the structure of Flutamide, a potent nonsteroidal antiandrogen prostate cancer drug. Novel bifunctional chelate-linked Flutamide analogues were prepared using a newly developed universal alkylating reagent, 2-bromo-N-[4-nitro-3-(trifluoromethyl)phenyl]-acetamide, 1. From compound 1, several ligands (i.e., cysteine 2, histidine 5, imidazole 3) were conjugated to the flutamide derivative to yield targeting ligands capable of either tridentate or monodentate coordination in a "2 + 1" complex. fac-Re(CO)(3)+ complexes were prepared and characterized with the functionalized conjugates to yield fac-Re(CO)(3)(2-amino-3-(1-(2-(4-nitro-3-(trifluoromethyl)phenylamino)-2-oxoethyl)-1H-imidazol-4-yl) propanoate), 4, fac-Re (CO)(3)(2-(S-cysteinyl)-N-[4-nitro-3-(trifluoromethyl) phenyl]-acetamide), 6, and fac-Re(CO)(3)(picolinate)(2-(1H-imidazol-1-yl)-N-[4-nitro-3-(trifluoromethyl)phenyl]-acetamide), 7. The corresponding radioactive 99mTc analogues were prepared and stability studies of the radioactive compounds were also conducted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.