Imidazo pyridines lithiation

Lithiation of compounds 8.110 generally takes place at the 2-position [as, e.g., in thieno[3,2-b]pyridine (84JHC785), furo[3,2-c]pyridine (83T1777), and thieno[2,3-b]pyridine (74JHC355)]. However, in thie-no[2,3-6]pyrazine lithiation occurs at the 5- and 6-positions in a 17 83 ratio (80JHC1019). Compounds of type 8.111 undergo lithiation as follows imidazo[l,2-[Pg.236]

Several new polychlorinated imidazo[l,2-a]pyridine C-nucleosides have been prepared by condensation of lithiated imidazo[ 1,2-a]pyridines with protected ribonolactones. It was established that, unexpectedly, the site of attachment was to the C-5 position <97JOC3453>. 

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