Rhodium-Catalyzed sp2 C-H Acetoxylation of N-Aryl Azaindoles/N-Heteroaryl Indolines

J Org Chem. 2017 Dec 1;82(23):12406-12415. doi: 10.1021/acs.joc.7b02203. Epub 2017 Nov 7.

Abstract

A silver- and copper-free rhodium-catalyzed C-H acetoxylation reaction of azaindoles has been achieved at near ambient temperature employing PIDA as a nonmetallic acetoxy source. The method is highly selective, efficient, and scalable and requires acetic anhydride as the sole additive. The scope of the reaction has been successfully tested with a wide array of medicinally important heterocyclic scaffolds with diverse functional group tolerance. A series of kinetic experiments was conducted to gain detailed insight into the reaction mechanism. The methodology developed could be successfully expanded for C7-acetoxylation of indoline derivatives using pyrimidine as a detachable directing group for the synthesis of 7-hydroxyindole.

Publication types

  • Research Support, Non-U.S. Gov't