Andrei Shavnya

Synthesis of sulfones from organozinc reagents, DABSO, and alkyl halides.

Organozinc reagents react with the SO2 surrogate DABSO, and the resulting zinc sulfinate salts are alkylated in situ to afford sulfones. This transformation has a broad scope and is compatible with a wide range of structural motifs of medicinal chemistry relevance including nitrile, secondary carbamates, and nitrogen-containing heterocycles.

Palladium-Catalyzed Sulfination of Aryl and Heteroaryl Halides: Direct Access to Sulfones and Sulfonamides

A novel palladium-catalyzed sulfination of aryl and heteroaryl halides is described. This reaction operates under mild conditions and provides access to a wide range of aryl and heteroaryl sulfinates, a useful and versatile class of synthetic intermediates. Capitalizing on this sulfination reaction, one-pot protocols allowing direct access to sulfones and sulfonamides have also been developed. The practicality of these transformations is illustrated with the parallel synthesis of analogues of the drug Viagra.

Discovery of PF-04449913, a Potent and Orally Bioavailable Inhibitor of Smoothened.

Inhibitors of the Hedgehog signaling pathway have generated a great deal of interest in the oncology area due to the mounting evidence of their potential to provide promising therapeutic options for patients. Herein, we describe the discovery strategy to overcome the issues inherent in lead structure 1 that resulted in the identification of Smoothened inhibitor 1-((2R,4R)-2-(1H-benzo[d]imidazol-2-yl)-1-methylpiperidin-4-yl)-3-(4-cyanophenyl)urea (PF-04449913, 26), which has been advanced to human clinical studies.

Comparative structure–activity relationship studies of 1-(5-methylsulfonylpyrid-2-yl)-5-alkyl and (hetero)aryl triazoles and pyrazoles in canine COX inhibition

Structure-activity relationship (SAR) studies of novel 5-alkyl and 5-aryl/heteroaryl substituted 1,2,4-triazoles are described. The in vitro activity is compared to the pyrazole class of compounds with analogous side chains to delineate the contribution of the triazole ring nitrogen in binding to the active site. Both series are quite potent and selective in the canine whole blood (CWB) COX-2 assay, suggesting the increased binding contribution of the hydrophobic side chains.

Structure-activity relationships and hepatic safety risks of thiazole agonists of the thrombopoietin receptor.

5-F substitution of an aminothiazole moiety within a series of thrombopoietin receptor agonists leads to potent agents with an improved hepatic safety profile in rodent toxicology studies.

The identification of orally bioavailable thrombopoietin agonists.

Recently, we disclosed a series of potent pyrimidine benzamide-based thrombopoietin receptor agonists. Unfortunately, the structural features required for the desired activity conferred physicochemical properties that were not favorable for the development of an oral agent. The physical properties of the series were improved by replacing the aminopyrimidinyl group with a piperidine-4-carboxylic acid moiety. The resulting compounds possessed favorable in vivo pharmacokinetic properties, including good bioavailability.