Relay catalysis by a metal-complex/brønsted acid binary system in a tandem isomerization/carbon-carbon bond forming sequence

A one-pot tandem isomerization/carbon-carbon bond forming sequence catalyzed by a ruthenium complex/Brønsted acid binary system is demonstrated. The method enables the use of readily available allylamides to deliver reactive imines under relay catalysis using a binary catalytic system. Subsequent Brønsted acid catalyzed carbon-carbon bond forming reactions of the generated imines with nucleophilic components afforded Friedel-Crafts and Mannich products in good yields.