Functionalization of Imidazo[1,2‐a]pyridines by Means of Metal‐Catalyzed Cross‐Coupling Reactions

Abstract

This review surveys recent developments (reported in the last fifteen years) in organometallic-chemistry-based methods for the functionalization of imidazo[1,2-a]pyridines, in particular the decoration of the pyridine and imidazole rings by means of reactions such as Sonogashira, Heck, Negishi, Suzuki-Miyaura, and Stille cross-coupling, as well as by C-

Copper‐Promoted Annulation of Terminal Alkynes with 2‐Aminopyridines to Assemble 2‐Halogenated Imidazo[1,2‐a]pyridines

“…At the beginning of our work, we chose 2aminopyridine 1a and phenylacetylene 2a as the model reactants to optimize the reaction conditions. Initially, we heated 1a (1.5 mmol), 2a (0.5 mmol), and CuBr 2 (0.5 mmol) in DCE at 90°C for 12 h, and we isolated product 3a in 53% yield ( [11][12][13]. Then we tried to use 1 equiv of KBr as the bromine source in combination with catalytic amount of Cu (OTf) 2 or Cu (OAc) 2 but found that the yield decreased slightly (entries [14][15].…”

“…In the past decades, imidazo[1,2‐ a ]pyridines have exhibited significant biological activities as well as broad application in material field , and much attention has been drawn to their syntheses . Among these compounds, halogenated imidazo[1,2‐ a ]pyridines are important synthetic target molecules and can be transformed into various functionalized imidazo[1,2‐ a ]pyridines via Heck coupling , Sonogashira coupling , Suzuki coupling , Stille coupling , and so on.…”

Metal Catalyzed Suzuki-Miyaura Cross-Coupling– Efficient Methodology for Synthesis the Natural and non-Natural biological active Molecules

“…Moreover, the imidazo[1,2-a]pyridine derivative Olprinone is available as an inhibitor of PDE 3/436, whereas Zolimidine has a gastroprotective effect and is used to treat peptic ulcers. Recently, several other experimental molecules have been reported as promising drugs [35].…”

NIS‐promoted multicomponent reaction of 2‐aminopyridines with aldehydes and nitromethane for the synthesis of 3‐nitroimidazo[1.2‐a]pyridines

“…[9][10][11] Hence, the syntheses of these compounds have drawn significant attention in the past decade. [12][13][14][15][16][17][18][19][20][21][22] As an important class of imidazopyridine derivatives, 3-nitroimidazo[1. 2-a]pyridines are attractive synthetic target molecules.…”