Synthesis of Pyridines by Carbenoid-Mediated Ring Opening of 2H-Azirines

Roaming the range: The title reaction tolerates a wide range of substituents on the resulting pyridine ring using mild reaction conditions (see scheme; esp=α,α,α′,α′‐tetramethyl‐1,3‐benzenedipropionic acid). The formation of the key intermediate is catalyst‐controlled, and subsequent cyclization and oxidation affords pyridines in excellent yields. The method has been used for the efficient synthesis of polyarylpyridines.