A Direct Oxidation of Diarylalkynes Containing Quinazolinones to 1,2-Diketone Derivatives with PIFA and PhSeSePh.

A simple and effective (bis-(trifluoroacetoxy)-iodo) benzene (PIFA) and organoselenium comediated aerobic oxidative reaction of 3-(2-(ethynyl)-aryl) quinazolinones for the synthesis of 1-(2-(4-oxoquinazolin-3-(4H)-yl) phenyl)-2-phenylethane-1,2-diones has been developed. The regioselective reaction proceeds smoothly under metal-free and catalyst-free conditions and provides 1,2-diketones with high chemoselectivity. The wide substrate scope can be applied by experimental studies to afford 1,2-diketones in good yields. A possible pathway for this transformation is proposed on the basis of the preliminary mechanistic investigation, which indicated a radical process.