Synthesis of a precursor for polymer backbone transformation via quinoline <i>N</i> -oxidation and subsequent C–H activation

Abstract Poly[(quinoline N-oxide)-2,3-diylmethylene] (PQOM), a well-defined polymeric precursor, was successfully synthesized through quantitative oxidation of poly(quinoline-2,3-diylmethylene) without any detectable side reactions. The resulting PQOM incorporates reactive quinoline N-oxide units along its main chain, which enabled selective C–H activation at the C8 position. This reactivity was demonstrated through the quantitative introduction of dimethyl malonate groups. These results establish PQOM not only as a cleanly preparable polymer but also as a versatile platform for post-polymerization backbone transformations, advancing the concept of chemical structure reprogramming in polymer chemistry.