LAUSR

Isoxazolopyridines are highly significant for the development of pharmaceutics and new materials. In continuation of our ongoing research on transformations of 5‐aminoisoxazoles, herein we report a divergent synthesis of two kinds of novel isoxazolo[5,4‐b]pyridines via condensation of 5‐aminoisoxazoles with β,γ‐alkynyl‐α‐imino esters. By using two different silver salts and a phosphoric acid as catalysts, isoxazolo[5,4‐b]pyridine‐α‐carboxylates and isoxazolo[5,4‐b]pyridine‐γ‐carboxylates were constructed as major isomers in moderate to good yields respectively. The structures of the two kinds of the isoxazolo[5,4‐b]pyridines were confirmed by X‐ray crystal structural analyses. Furhermore, control experiments were conducted to elucidate the reaction mechanism.