Assembly of pentacyclic pyrido[4,3,2-mn]acridin-8-ones via a domino reaction initiated by Au(I)-catalyzed 6-endo-dig cycloisomerization of N-propargylaminoquinones

A novel methodology taking advantage of a domino reaction initiated by an Au(I)-catalyzed 6-endo-dig cycloisomerization under silver-free condition was developed to prepare pentacyclic pyrido[4,3,2-mn]acridin-8-ones from N-propargylaminoquinones. Triphenylphosphinegold(I) chloride in combination with TFA was firstly employed and displayed excellent catalytic efficiency in the domino reaction.