DMAP‐Catalyzed C—N Bond Formation for Diverse Synthesis of Imidazo[1,2‐a]pyrimidine and Pyrimido[1,2‐a]benzimidazole Derivatives

Abstract

of main observation and conclusion A DMAP (2-dimethylaminopyridine)-catalyzed condensation reactions for the successful direct construction of pyrimido[1,2-a]benzimidazole or imidazo[1,2-a]pyrimidine has been developed. The method utilizes readily available α-bromocinnamaldehydes with 2-aminobenzimidazole or 2-aminoimidazole as starting materials in the presence of 2-DMAP/TBHP. In the process, two C-N bonds were successfully constructed to synthesize target compounds. The current method features wide substrate scope, product diversification, and metal-free conditions.

Design, synthesis, molecular docking, and in vitro α-glucosidase inhibitory activities of novel 3-amino-2,4-diarylbenzo[4,5]imidazo[1,2-a]pyrimidines against yeast and rat α-glucosidase

“…Among them, the reactions of 2-aminobenzimidazole with appropriate electrophilic compounds are the most traditional routes. Some noticeable examples include the reaction of this starting material with α , β -unsaturated compounds 44 , 1,2-diphenylethanones, alkynes, or 1,3-bis electrophilic compounds and aromatic aldehydes 45 – 50 , acrylamides bearing a leaving group like ethoxy in the β -position 51 , domino reaction with N-methyl-1-(methylthio)-2-nitroprop-1-en-1-amine and aromatic aldehydes 52 , as well as four-component reaction with amines, diketene, and aromatic aldehydes 53 .…”

Synthesis of Substituted of Benzo[4,5]imidazo[1,2-a]pyrimidines through (3 + 2+1) Cyclization of 2-Aminobenzimidazole, Acetophenone, and N,N-Dimethylformamide as One-Carbon Synthon

“…Next, Chai and co-workers disclosed the CuI-catalyzed cyclization reaction of 2-aminobenzimidazole, aldehydes, and alkynecarboxylic acids to obtain benzo[4,5]imidazo[1,2- a ]pyrimidines (Scheme b) . Besides, Liu et al divulged an efficient approach for the synthesis of pyrimido[1,2- a ]benzimidazole derivatives from 2-aminobenzimidazoles and α-bromocinnamaldehydes by employing 4-dimethylaminopyridine (DMAP) as the catalyst (Scheme c) . However, most methods exist with some limitations, including slow reaction times, the use of hazardous catalysts, and cumbersome subsequent processing.…”

Design, Synthesis, Molecular Docking, and Kinetic Study of 3-Amino-2,4-Diarylbenzo[4,5]Imidazo[1,2-a]Pyrimidines as Novel, Potent Α-Glucosidase Inhibitor

“…Among them, the reactions of 2-aminobenzimidazole with appropriate electrophilic compounds are the most traditional routes. Some noticeable examples include the reaction of this starting material with α,β-unsaturated compounds 44 , 1,2diphenylethanones, alkynes, or 1,3-bis electrophilic compounds and aromatic aldehydes [45][46][47][48][49][50] , acrylamides bearing a leaving group like ethoxy in the β-position 51 , domino reaction with N-methyl-1-(methylthio)-2-nitroprop-1-en-1-amine and aromatic aldehydes 52 , as well as four-component reaction with amines, diketene, and aromatic aldehydes 53 .…”