Tandem Diels–Alder/oxidation–aromatization reactions involving 2-styrylchromones and arynes

Abstract

Transition-metal-free Diels–Alder and tandem Diels–Alder/oxidation–aromatization reactions of 2-styrylchromones with arynes have been demonstrated under mild reaction conditions with a wide range of substrates. The tandem process afforded functionalized benzo[c]xanthone derivatives in moderate to good yields. This efficient protocol allows rapid access to either dihydrobenzo[c]xanthone and benzo[c]xanthone derivatives selectively by simply changing the atmosphere of the reaction.