CPA-catalyzed enantioselective synthesis of α,α-bisindoles-assembled triarylmethanes between 3-indolyl[1,4]thiazepines and indoles via ring-opening/friedel-crafts reaction.

We describe that a type of new and flexible 3-indolyl[1,4]thiazepines can be efficiently merged with substituted indoles catalyzed by chiral phosphoric acid (CPA), providing a range of structurally diverse α,α-bisindoles-assembled triarylmethanes in excellent diastereomeric and enantiomeric excess (up to 92% de, > 99% ee), excellent yields, and 100% atom economy. These reactions harness the ability of 3-indolyl[1,4]thiazepines to form active species via a ring-opening process involving the cleavage of C-N bond that are subsequently trapped by nucleophilic indoles via Friedel-Crafts reaction. The late-stage modification, and identification of partial products exhibiting good anticancer activities highlights the utility of this methodology.