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Vandetanib (ZD6474) and its chlorine analogue chloro-Vandetanib are potent and selective vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors with low nanomolar IC50 values. [11C]Vandetanib and [11C]chloro-Vandetanib, new potential PET agents for imaging of VEGFR in cancer, were first designed, synthesized and labeled at nitrogen and oxygen positions from their corresponding N- and O-des-methylated precursors, in 40–50% decay corrected radiochemical yield and 370–555 GBq/μmol specific activity at end of bombardment (EOB).

The title compounds have been synthesized in a convergent way by recourse to a Weiler type dianion construction.

The synthesis and biological evaluation of about one dozen 7-silylcamptothecin derivatives are described. Most new compounds show potencies comparable to or better than camptothecin itself. The best compound, 11-fluoro-10-amino-7-trimethylsilylcamptothecin, is more than 20 times more potent than camptothecin in cell assays.

Solid-liquid phase transfer catalytic elimination reaction for the preparation of acyclic and cyclic ketene acetals has been developed.

Neutral Fischer carbene complexes bearing alkyloxy groups have been synthesized by direct alkylation of the lithium acylmetalates with alkyl iodides under solid-liquid phase transfer catalysis (PTC).

A direct iodination method with iodine and silver triflate for the synthesis of SPECT and PET imaging agent precursors has been developed.

The estrogen receptors (ERs) are attractive targets in the treatment of breast cancer and the development of receptor-based breast cancer imaging agents for diagnostic use in biomedical imaging technique positron emission tomography (PET). Tetrahydroisoquinoline derivatives are a class of selective estrogen receptor modulators (SERMs) with high binding affinity and specificity exhibiting up to 50 folds for ERα over ERβ. New carbon-11 labeled tetrahydroisoquinoline derivatives, [11C]methyl 1-(2-(4-(2-(4-fluorophenyl)-6-hydroxy-1-methyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenoxy)ethyl)piperidine-4-carboxylate ([11C]10a) and [11C]methyl 1-(2-(4-(2-(4-chlorophenyl)-6-hydroxy-1-methyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenoxy)ethyl)piperidine-4-carboxylate ([11C]10b), have been first designed, synthesized and evaluated. The target tracers were prepared by O-[11C]methylation of their corresponding precursors using [11C]CH3OTf and isolated by solid-phase extraction (SPE) purification procedure in 40–60% radiochemical yields, which were decay corrected to the end of bombardment (EOB), based on [11C]CO2. The overall synthesis time was 15–20 min from EOB. The radiochemical purity was >99%, and specific activity was in a range of 74–111 GBq/μmol at the end of synthesis (EOS). Preliminary findings from in vitro biological assay indicate that the synthesized derivatives displayed similar potencies in the MCF-7 human breast cancer cell line in comparison with 4-hydroxytamoxifen, a well-known potent SERM. These results encourage further in vivo evaluation of carbon-11 labeled tetrahydroisoquinoline derivatives as new potential SERM radioligands for PET imaging of ER expression in breast cancer.

The reaction of iso-propoxy stabilized Fischer carbene complexes with ketene acetals gives moderate to excellent yields of cyclopropanone acetals when carried out under a carbon monoxide atmosphere. This is in contrast to the known reaction of methoxy substituted complexes which give cyclic ortho esters under the same conditions. A mechanism is proposed which involves a branch point between the two products as the zwitterionic intermediate resulting from nucleophilic addition of the ketene acetal to the carbene carbon. A 1,3-migration of the methoxyl group to the cationic center leads to the ortho ester and a ring closure by backside attack leads to the cyclopropanone acetal. A double-labeling experiment shows that the 1,3-migration occurs by an intramolecular process that is proposed to involve a bridging oxonium ion. The effect of the isopropoxy group is thus interpreted to be to sterically hinder the formation of a bridged oxonium ion.