An Oxygen Walk Approach for C3 Selective Hydroxylation of Pyridines.

Selective C3 functionalization of unbiased pyridines represents a significant challenge in organic synthesis. While seminal work in this area has enabled access to various C3-substituted pyridines via dearomatized intermediates, the direct introduction of a hydroxy group at this position is still challenging. In this context, we have developed a valence isomerization reaction triggered by photoexcitation of pyridine N-oxides to deliver synthetically challenging C3-hydroxy pyridine products.