Palladium catalyzed coupling of 2,6-Dichloro-3-iodoimidazo[1,2-a]pyridine and 2,3-dihydrofuran as an approach to novel imidazo[1,2-a]pyridine C-nucleosides

Palladium was used for a cross coupling of 2,6-dichloro-3-iodoimidazo[1,2-a]pyridine (2) to 2,3-dihydrofuran (3). Optimization of the coupling conditions have given exclusively (+/−)-2,6-dichloro-3-(2′,5′-dihydrofuran-2′-yl)imidazo[1,2-a]pyridine (4) in high yield. Compound 4 was dihydroxylated using a catalytic amount of osmium tetroxide to give the erythrofuranosyl C-nucleoside derivatives 6 and 7. This is the first report of a C-nucleoside derivative containing a sugar moiety attached to the C3 position of an imidazo[1,2-a]pyridine heterocycle.