Pd(II)-Catalyzed Cascade Annulation of o-Aminobenzoic Acids with CO, Amines, and Aldehydes to N3-/N1,N3-Substituted 2,3-Dihydroquinazolin-4(1H)-ones

Abstract

The unprecedented Pd(II)-catalyzed cascade annulation of o-aminobenzoic acids with CO, amines, and aldehydes has been developed. This protocol provides an efficient and concise approach to selective construction of N3-substituted and N1,N3disubstituted 2,3-dihydroquinazolin-4(1H)-ones mostly in moderate to excellent yields from simple and easily available starting materials under mild conditions featured with low cost, high step economy, broad substrate scope, and good product diversity.

Pd(ii)-catalyzed cascade annulation of N-substituted anilines with CO, NH4OAc and aldehydes to N1-substituted 2,3-dihydroquinazolin-4(1H)-ones

“…11,12 Recently, we have also successfully developed new approaches to N 1, N 3-disubstituted DHQs and N 3-/ N 1, N 3-substituted DHQs via Pd-catalyzed one-pot annulation of N -substituted anilines or o -aminobenzoic acids with CO, amines and aldehydes. 13 Inspired by these results, we envision that N 1-substituted DHQs could also be generated via Pd-catalyzed one-pot annulation of N -substituted anilines with CO, ammonium acetate and aldehydes (Scheme 3). This protocol, with the N -substituted amino group as the intrinsic directing group and with the advantages of Pd-catalyzed carbonylation and cascade reactions, has not been reported in the literature so far to the best of our knowledge and will, if realized, lead to the development of a new facile and efficient approach to N 1-substituted DHQs featuring cheap and easily obtainable raw materials, low cost, high atom/step economy and efficiency, broad substrate scope and good product diversity.…”