Multicatalytic synthesis of 1,2-dihydroisoquinolin-1-ylphosphonates via a tandem four-component reaction

A tandem four-component reaction of 2-bromobenzaldehyde, alkyne, amine, and diethyl phosphite catalyzed by the combination of palladium and copper salts provides a facile and efficient route to 1,2-dihydroisoquinolin-1-ylphosphonate. A cascade Sonogashira-intramolecular cyclization-nucleophilic addition may be involved in the reaction process.