The Vinyl Moiety as a Handle for Regiocontrol in the Preparation of Unsymmetrical 2,3-Aliphatic-Substituted Indoles and Pyrroles

摘要

Since their introduction in the 1880s, the Fischer indole synthesis (Scheme 1 a) and the Paal-Knorr pyrrole synthesis have ranked among the most utilized reactions in heterocyclic chemistry. However, the general importance of these heterocycles have driven chemists to continue developing novel methods to access differentially substituted indoles and pyrroles. Over 100 years later, Larock's indole synthesis (Scheme 1b) aptly highlighted the utility of transition-metal catalysis in the formation of aromatic heterocycles. In the subsequent decade, palladium has continued to play a central role in this diverse reaction class.