Novel Photoacid Generators Derived From Allomaltol Containing Terarylenes With 2‐Aminooxazole Fragment

ABSTRACT In this work, we report a new series of efficient neutral photoacid generators (PAGs) based on terarylenes with 2‐aminooxazole bridge fragment. These compounds are readily obtained through a straightforward two‐step approach starting from allomaltol. Wherein, the presence of a hydroxyl group of allomaltol in the terarylene framework enables facile modification with the residues of various acids. It was shown that upon UV‐irradiation such acylated products undergo 6π‐electrocyclization, giving rise to novel polycyclic aromatic compounds with simultaneous release of the corresponding acids. The regiospecificity of investigated process was confirmed by 1 H NMR monitoring. UV–vis absorption and fluorescence studies revealed a strong emission of the acylated precursors and a pronounced decrease in fluorescence upon photoconversion. The developed photoacid generators combine thermal stability, simple preparation procedure with a minimum number of synthetic stages, and effective acid release, which makes them promising for practical applications.