Construction of Bridged Carbocycles and Heterocycles via Rh(III)-Catalyzed C-H Alkylation/Michael Addition of 2-Arylindoles with Quinone Monoacetals

J Org Chem. 2020 Jul 17;85(14):8910-8922. doi: 10.1021/acs.joc.0c00774. Epub 2020 Jun 26.

Abstract

A rhodium-catalyzed formal [4 + 5] annulation reaction of 2-arylindoles with quinone monoacetals for the selective preparation of bridged nine-membered carbocyclic and heterocyclic compounds is developed. When 2-aryl substituted indoles are employed, this annulation reaction affords bridged nine-membered carbocyclic compounds with excellent indolyl C3 selectivity. On the other hand, with 2-aryl-3-substituted indoles as the substrates, bridged nine-membered heterocyclic compounds are exclusively formed via N1 annulation. Further transformations of the obtained products into new bridged compounds showcase the synthetic potential of this protocol.

Publication types

  • Research Support, Non-U.S. Gov't