A gold-catalyzed cycloisomerization/aerobic oxidation cascade strategy for 2-aryl indenones from 1,5-enynes.

A unique gold(I)-catalyzed 5-endo-dig cyclization/aerobic oxidation cascade strategy from 1,5-enyne substrates with molecular oxygen as the oxidant to yield the indenone was described. The reaction mechanism was studied by heavy atom labelling and some related experiments. This method was applied to the formal total synthesis of isoprekinamycin.