Successive Regioselective Metalations of Fused Heterocycles: Synthesis of Polyfunctionalized Furo[3,2‑<i>b</i>]pyridines

The furopyridine framework was chosen as a target for a lithiation study, in order to define the most effective conditions leading to the total functionalization of the heterocycle. Consequently, a detailed procedure for successive regioselective lithiations/electrophilic trapping of furo­[3,2-<i>b</i>]­pyridines is described and afforded several polyfunctionalized derivatives in good overall yields. A Pd-catalyzed cross-coupling reaction is also described and easily yielded the 7,7′-bifuro­[3,2-<i>b</i>]­pyridine