Manganese Catalysed Synthesis of Polyketones Using Hydrogen Borrowing Approach

We report here a new method to make polyketones from the coupling of diketones and diols using a manganese pincer complex. The methodology allows us to access a new type of polyketone (polyarylalkylketone) containing aryl, alkyl, and ether functionalities bridging the gap between the two classes of commercially available polyketones – aliphatic polyketones and polyaryletherketones. Using this methodology, twelve new polyketones have been synthesized and characterised using various analytical techniques to understand their chemical, physical, morphological, and mechanical properties. Based on previous reports and our studies, we suggest that the polymerization occurs via a hydrogen-borrowing mechanism that involves the dehydrogenation of diols to dialdehyde followed by aldol condensation of dialdehyde with diketones to form chalcone derivatives and their subsequent hydrogenation to form polyarylalkylketones.