Synthesis of Novel Substituted Benzimidazo[1,2-a]quinoxalin-6(5H)-ones via an Intramolecular Goldberg Reaction

One‐pot synthesis of benzimidazole‐pyrazines and their anticancer activities

“…Ghandi et al reported the synthesis of compound I as an example of an important type of pharmacologically active compound through an Ugi three‐component condensation (Ugi‐3CC) in high yields under simple work‐up procedures . Compound II was constructed via a Ugi/deprotection/cyclization (UDC) strategy, followed by a nucleophilic substitution reaction in good yields ; this compound was also reported to be obtained via an intramolecular Goldberg reaction in one step using CuI as a catalyst . On the other hand, compound III was synthesized by an efficient solid‐phase reaction via N ‐acyliminium ion cyclization‐nucleophilic addition under mild reaction conditions using commercially available starting materials .…”

“…The synthesis route was shown in Figure . As mentioned above, in another procedure, CuI was used as a catalyst starting from their self‐made intermediates . As a part of our continuous effort on drug discovery, we herein report a cascade reaction combining the UDC strategy and a hydroamination reaction using commercially available starting materials towards the synthesis of fused benzimidazole‐pyrazine compounds in a one‐pot protocol.…”

Synthesis of Constrained Heterocycles Employing Two Post‐Ugi Cyclization Methods for Rapid Library Generation with In Cellulo Activity

“…Previous synthetic methods have focused on adding additional rings directly to the heterocycles, or expanding at the 2, 5, or 6 position of benzimidazoles, or the 3, 6, and 7 position of quinoxalinones. [3] Interestingly, few combinatorial syntheses have focused on the N1 position of either molecule and, to the best of our knowledge, separate heterocycles have not been attached at this position. Therefore, methods to expand into new chemical space are highly valuable to generate molecules with novel biological and therapeutic properties.…”

“…[11] Particularly notable contributions have come from C. Hulme, A. Domling, and J. Zhu. [3e, 6a, d, 12] …”

Simple and Efficient Copper(I)‐Catalyzed Access to Three Versatile Aminocoumarin‐Based Scaffolds using Isocyanoacetate

“…[8] As part of our ongoing efforts to prepare novel fused imidazole ring systems, [9,10] which are of great interest to the pharmaceutical industry, we recently focused on the Groebke-Blackburn-BienaymØ multicomponent reaction or GBB-MCR (Scheme 1). [11] It involves the reaction of 2-aminopyridine, salicylaldehyde and ethyl isocyanoacetate, and is catalyzed by scandium triflate to afford 3-aminoimidazoA C H T U N G T R E N N U N G [1,2-a]pyridines in good yields (> 80%).…”