Enantioselective Domino Reaction of 3-Vinylindole and p-Quinone Methides Enabled by Chiral Imidodiphosphoric Acids: Asymmetric Synthesis of Multisubstituted 3-Indolyl Cyclopenta[b]indoles.

The development of a stereoselective method for the rapid assembly of structurally complex molecules remains fascinating and challenging in synthetic organic chemistry. Here, we report an enantioselective domino reaction between 3-vinylindole and p-quinone methide for the preparation of 3-indolyl cyclopenta[b]indoles containing multiple chiral centers. Chiral imidodiphosphoric acids enable this cascade asymmetric process, delivering a series of products with excellent yields (≤99%), enantioselectivities (≤99%), and diastereoselectivities (≤20:1 dr).