Formation and Uses of Imidazo[1,2-a]pyrimidines and Related Compounds: A Review Comprising Years 2000-2021

Abstract

This work covers the selected synthetic papers of imidazo[1,2-a]pyrimidine and its derivatives between the years 2000 and 2021. Synthesis of the heterocyclic moiety, application of this scaffold to biological activities, and secondary applications like corrosion inhibition are provided. The authors hope that readers will find the treatise useful.

Microwave-assisted synthesis and functionalization of 2-arylimidazo[1,2-a]pyrimidin-5(8H)-ones

“…The imidazo [1,5-a] pyrimidine ring can react with electrophiles at two places, but the p-excessive nature of imidazole favors position 3 over 6 in the pyrimidine core. Most electrophilic aromatic substitution (EAS) reactions lead to 3-substituted products, [18][19][20][21]43 but the alkyl group in 6a-e played a crucial role in their reactivity. Indeed, 3,6-dibrominated IPs 8a-e were easily obtained, while directed regioselectivity could not be achieved despite strict control of the reaction conditions.…”

“…of bromine for 1 hour at room temperature, compounds 8a-e were efficiently obtained (Scheme 6b). This type of compound would be useful in Pdcatalyzed C-C cross-coupling reactions, [18][19][20][21] and the reaction approach may spearhead future syntheses based on EAS reactions of the imidazo[1,2-a]pyrimidine ring.…”

“…[6][7][8][9][10] Although there are many works on imidazo[1,2-a]pyrimidine-ring-based compounds, this scaffold is part of diazolopyrimidines with minor applicability with few commercial compounds containing it. Thus, studying this type of compound is valuable since it has high and proven photophysical [9][10][11] and biological potential [12][13][14][15][16][17][18][19][20][21] (Fig. 1b).…”

“…Notably, the imidazo[1,2-a]pyrimidine (IP) motif has been found in molecules with antileishmanial, 12 anticancer, 13,14,17 antibacterial, 15 and antiinammatory 16 activities, and various ways of synthesizing imidazo[1,2-a]pyrimidines (IPs) have been developed. However, in addition to articles [9][10][11][12][13][14][15][16][17][22][23][24][25][26][27][28][29][30][31] and patents, 32,33 only few specialized reviews [18][19][20][21] on IPs are available.…”

“…Notably, the imidazo[1,2- a ]pyrimidine (IP) motif has been found in molecules with antileishmanial, 12 anticancer, 13,14,17 antibacterial, 15 and antiinflammatory 16 activities, and various ways of synthesizing imidazo[1,2- a ]pyrimidines (IPs) have been developed. However, in addition to articles 9–17,22–31 and patents, 32,33 only few specialized reviews 18–21 on IPs are available. These compounds generally allow structural changes at positions 2, 3, or 5–8 via ring building or functionalization with aromatic substituents, redox, or metal-mediated C–C coupling reactions.…”