Copper‐Catalyzed Oxidative [1+2+1+2] Cascade Cyclization of N,N‐Dimethyl Enaminones with Benzylamines: A Facile Access to Functionalized 1,4‐Dihydropyridines.

Using benzylamines as the C4 source of 1,4‐dihydropyridines (1,4‐DHPs), a Cu‐catalyzed oxidative [1+2+1+2] cascade cyclization for the synthesis of 1,4‐DHPs was firstly developed. A broad range of easily available N,N‐dimethyl enaminones and benzylamines are employed smoothly to provide a diverse range of 1,4‐DHPs with high efficiency. This method is performed by a one‐pot cascade C(sp3)−H bond functionalization/C(sp3)−N cleavage/cyclization strategy to form simultaneously two C(sp3)−C(sp2) bonds, two C(sp2)−N bonds, and a 1,4‐DHP ring. [ABSTRACT FROM AUTHOR]