Diastereoselective Indole-Dearomative Cope Rearrangements by Compounding Minor Driving Forces
Subhadip De, Breanna Tomiczek, Yinuo Yang, Kenneth Ko, Ion Ghiviriga, Adrián E. Roitberg, Alexander J. Grenning
Abstract
Reported herein is the discovery of a diastereoselective indole-dearomative Cope rearrangement. A suite of minor driving forces promote dearomatization: (i) steric congestion in the starting material, (ii) alkylidene malononitrile and stilbene conjugation events in the product, and (iii) an unexpected intramolecular π-π* stack on the product side of the equilibrium. The key substrates are rapidly assembled from simple starting materials, resulting in many successful examples. The products are structurally complex and bear vicinal stereocenters generated by the dearomative Cope rearrangement. They also contain a variety of functional groups for interconversion to complex architectures.