Hydrated ferric sulfate-catalyzed reactions of indole with aldehydes, ketones, cyclic ketones, and chromanones: Synthesis of bisindoles and trisindoles

Noland, W. E.; Kumar, H. V.; Flick, G. C.; Aspros, C. L.; Yoon, J. H.; Wilt, A. C.; Dehkordi, N.; Thao, S.; Schneerer, A. K.; Gao, S.; Tritch, K. J. Tetrahedron, 2017, 73, 3913.