Functional poly(1,4-ketone)s with pendant hydroxy moieties, 1: Pd(II)-catalyzed alternating copolymerization of carbon monoxide and allylbenzene derivatives

Functional poly(1,4-ketone)s were prepared by alternating copolymerization of carbon monoxide with substituted allylbenzenes, namely 2-allylphenol 1, 2-allyl-4-methylphenol 2, 2-allyl-6-methylphenol 3, 2-allylmethoxybenzene 4, 2-allylethoxybenzene 5, 2-allylacetoxybenzene 6 and 4-allylmethoxybenzene 7. The dicationic Pd(II) bis(phosphine) complex [Pd(DPPP)(CH₃CN)₂] (BF₄)₂ 10 [DPPP= 1,3-bis(diphenylphosphino)propane] was used as the catalyst precursor. Optimum results occurred with monomers that bear oxygen-containing substituents located in ortho-position to the allyl group. Copolymers derived from phenolic monomers structurally differ from their protected analogues because they predominantly display ketalic character due to nucleophilic attack of the OH groups towards neighbored keto moieties. Pendant hydroxy moieties of functional poly(1,4-ketone)s were reacted with chlorides and anhydrides of carboxylic acids to form the corresponding esters as a model reaction for grafring processes. Furthermore, isocyanates were used in terms of post-polymerization functionalization.