Assembly of unsymmetrical 1,3,5-triarylbenzenes via tandem reaction of β-arylethenesulfonyl fluorides and α-cyano-β-methylenones

A transition-metal-free tandem reaction of β-arylethenesulfonyl fluorides and α-cyano-β-methylenones has been revealed. In the presence of cesium carbonate, 2-arylethenesulfonyl fluorides react with α-cyano-β-methylenones through a tandem Diels-Alder cycloaddition/sulfur (VI) fluoride exchange/elimination process to afford cyclohexadiene, which further undergoes decyanolative aromatization in one-pot to produce 1,3,5-triarylbenzenes in moderate to good yields. In addition, direct oxidative aromatization of cyclohexadiene intermediate will construct 2,4,6-triarylbenzonitriles.