Synthesis of and Metal Complexation with a Chiral Cyclam.

Tetraazamacrocycles, like cyclam 1, are well-studied polyamine ligands for metal ions that were first developed to model biological processes. Despite being studied for nearly 60 years, the development of chiral variants of 1 has been limited. We report the synthesis of a chiral variant of 1, the tetraazamacrocycle 2. Outlined herein are the synthesis of 2, a preliminary study of its complexation with metal ions, and the properties of the resulting metal complexes.

Synthesis and Applications of the C2-Symmetrical Diamine 2,7-Diazabicyclo[4.4.1]undecane.

Chiral diamines are particularly useful as ligands for asymmetric catalysis. In an effort to expand the library of such diamines, the synthesis and resolution of the C2-symmetric diamine 2,7-diazabicyclo[4.4.1]undecane [(-)-1] are reported. Diamine (-)-1 has been prepared in multigram quantities from the known bicyclic diketone 7 in four steps without the need for chromatographic purification. Derivatives of (-)-1, i.e., the bis-methylated diamine (+)-5 and two diastereomeric tricyclic analogs, were evaluated as potential sparteine surrogates. The solid-state structure of the (+)-5-methyllithium complex was obtained. High levels of asymmetric induction were observed while using (+)-5 as a ligand in palladium-mediated asymmetric allylations.

A 3-(4-nitronaphthen-1-yl) amino-benzoate analog as a bifunctional AKR1C3 inhibitor and AR antagonist: Head to head comparison with other advanced AKR1C3 targeted therapeutics.

Drugs used for the treatment of castration resistant prostate cancer (CRPC) include Abiraterone acetate (Zytiga®) and Enzalutamide (XTANDI®). However, these drugs provide clinical benefit in metastatic disease for only a brief period before drug resistance emerges. One mechanism of drug resistance involves the overexpression of type 5 17-ß-hydroxysteroid dehydrogenase (aldo-keto reductase 1C3 or AKR1C3), a major enzyme responsible for the formation of intratumoral androgens that activate the androgen receptor (AR). 3-((4-Nitronaphthalen-1-yl)amino)benzoic acid 1 is a "first-in-class" AKR1C3 competitive inhibitor and AR antagonist. Compound 1 was compared in a battery of in vitro studies with structurally related N-naphthyl-aminobenzoates, and AKR1C3 targeted therapeutics e.g. GTx-560 and ASP9521, as well as with R-bicalutamide, enzalutamide and abiraterone acetate. Compound 1 was the only naphthyl derivative that was a selective AKR1C3 inhibitor and AR antagonist in direct competitive binding assays and in AR driven reporter gene assays. GTx-560 displayed weak activity as a direct AR antagonist but had high potency in the AR reporter gene assay consistent with its ability to inhibit the co-activator function of AKR1C3. By contrast ASP9521 did not act as either an AR antagonist or block AR reporter gene activity. Compound 1 was the only compound that showed comparable potency to inhibit AKR1C3 and act as a direct AR antagonist. Compound 1 blocked the formation of testosterone in LNCaP-AKR1C3 cells, and the expression of PSA driven by the AKR1C3 substrate (4-androstene-3,17-dione) and by an AR agonist, 5α-dihydrotestosterone consistent with its bifunctional role. Compound 1 blocked the nuclear translocation of the AR at similar concentrations to enzalutamide and caused disappearance of the AR from cell lysates. R-biaclutamide and enzalutamide inhibited AKR1C3 at concentrations 200x greater than compound 1, suggesting that its bifunctionality can be explained by a shared pharmacophore that can be optimized.