Iodine as Polarity-Reversal Catalyst: Synthesis of a Fused Heterocycle with Contiguous Stereocenters.

We report an unconventional I-catalyzed cascade reaction for the synthesis of angular triquinane derivatives with a fused heterocycle skeleton, leveraging enaminones and anilines as simple acyclic precursors. The key to success lies in I functioning as a polar-reversal catalyst, which alters the reactivity at the α-position of the enaminone and facilitates the first hexa-functionalization of an enaminone along with the formation of highly congested continuous stereocenters.