Pd(II)-Catalyzed 3 + 1 + 1 + 1 Cascade Annulation of N -Substituted Anilines with CO and Amines: Direct Access to N 1, N 3-Disubstituted Quinazoline-2,4(1 H ,3 H )-diones

In this study, we present an efficient and direct strategy for the synthesis of N1,N3-disubstituted quinazoline-2,4(1H,3H)-diones with high atom and step economy. The protocol involves a Pd(II)-catalyzed 3 + 1 + 1 + 1 cascade carbonylation/amidation/cyclocarbonylation reaction, wherein the alkylamino moiety of simple N-substituted anilines serves as an intrinsic directing group, with CO and amines as the coupling partners. This cascade process proceeds smoothly with a variety of substrates under mild conditions, affording the target products with either identical or distinct substituents mostly in moderate to good yields.