Palladium-Catalyzed Tandem Alkenyl and Aryl C?N Bond Formation: A Cascade N-Annulation Route to 1-Functionalized Indoles

Multicomponent assembly of highly substituted indoles by dual palladium-catalyzed coupling reactions

Highly substituted indoles were synthesized by a palladium-catalyzed reaction involving three independent components in a one-pot reaction. Two distinct palladium-catalyzed coupling reactions occur with a single catalytic system: a Buchwald-Hartwig reaction and an arene-alkene coupling. Quantum chemical computations provide insight into the mechanism of the latter coupling step.

Recent advances in the synthesis of indole and quinoline derivatives through cascade reactions

Indoles and quinolines are ubiquitous structural motifs in many natural products and biologically active pharmaceuticals. The pursuit of synthetic efficiency has stimulated the design and development of new synthetic strategies to construct these heterocycles. One of the most effective ways of achieving efficiency is to implement reaction cascades, enabling multiple bond-forming and bond-cleaving events to occur in a single synthetic operation, thus circumventing the waste associated with traditional stepwise synthesis. In general, cascade reactions offer the opportunity to access highly functionalized final products from simple starting materials. For all these reasons, it is not a surprise that most of the recently reported methods for the synthesis of indoles and quinolines are based on the use of cascade reactions. In this Focus Review we discuss some of the most representative and interesting recent reports on the synthesis of indoles and quinolines through cascade reactions.