Base-Free Synthesis and Synthetic Applications of Novel 3-(Organochalcogenyl)prop-2-yn-1-yl Esters: Promising Anticancer Agents

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 conditions. Generally, the reactions have proceeded very smoothly, being tolerant to a 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 bond. Moreover, the 3-(phenyl­selanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.

Access to a Phthalazine Derivative Through an Angular cis-Quinacridone

Intramolecular electrophilic cyclization of a bisanthranilate afforded an angular cis-quinacridone compound, which condensed with hydrazine to give a phthalazine derivative. A [2+2+2] cyclization reaction occurred at the C-N double bond position of phthalazine when reacted with dimethyl acetylenedicarboxylate. The structures of these novel compounds were confirmed by crystallographic analysis. The phthalazine derivative decomposes back to quinacridone at ambient condition in the dark and as a solid with a half lifetime of about 22 months.