Synthesis of Substituted Carbazoles, Indoles, and Dibenzofurans by Vinylic to Aryl Palladium Migration
journal contributionposted on 07.07.2006, 00:00 by Jian Zhao, Richard C. Larock
Substituted carbazoles, indoles, and dibenzofurans are readily prepared in moderate to excellent yields by the palladium-catalyzed cross-coupling of alkynes and appropriately substituted aryl iodides. This process proceeds by carbopalladation of the alkyne, heteroatom-directed vinylic to aryl palladium migration, and ring closure via intramolecular arylation or a Mizoroki−Heck reaction. Results from the deuterium labeling experiments are consistent with the proposed mechanism.