This manuscript portrays the CuI-catalyzed Csp-chalcogen bond formation through cross-coupling reactions of propynyl esters and diorganyl dichalcogenides by using DMSO as solvent, at room temperature, under base-free and open-to-air atmosphere. Generally, the reactions have proceeded very smoothly, being tolerant to range of substituents present in both substrates, affording the novel 3-(organochalcogenyl)prop-2-yn-1-yl esters in moderate to good yields. Noteworthy, the 3-(butylselanyl)prop-2-yn-1-yl benzoate proved to be useful as synthetic precursor in palladium-catalyzed Suzuki and Sonogashira type cross-coupling reactions by replacing the carbon-chalcogen bond by new carbon-carbon bonds. Moreover, the 3-(phenylselanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.
SYNTHESIS OF N-(tert-BUTOXYCARBONYL)-a-IODOALANINE METHYL ESTER: A USEFUL BUILDING BLOCK IN THE SYNTHESIS OF NONNATURAL a-AMINO ACIDS VIA PALLADIUM CATALYZED CROSS COUPLING REACTIONS