Efficient Transformation of Polymer Main Chain Catalyzed by Macrocycle Metal Complexes via Pseudorotaxane Intermediate

Angew Chem Int Ed Engl. 2023 Jun 12;62(24):e202303494. doi: 10.1002/anie.202303494. Epub 2023 May 4.

Abstract

Post-synthesis modification of polymers streamlines the synthesis of functionalized polymers, but is often incomplete due to the negative polymer effects. Developing efficient polymer reactions in artificial systems thus represents a long-standing objective in the fields of polymer and material science. Here, we show unprecedented macrocycle-metal-complex-catalyzed systems for efficient polymer reaction that result in 100 % transformation of the main chain functional groups presumably via a processive mode reaction. The complete polymer reactions were confirmed in not only intramolecular reaction (hydroamination) but also intermolecular reaction (hydrosilylation) by using Pd- and Pt-macrocycle-catalyzed systems. The most fascinating feature of the both reactions is that higher-molecular-weight polymers reach completion faster. Various studies suggested that the reactions occur in the catalyst cavity via the formation of a supramolecular complex between the macrocycle catalyst and polymer substrate like pseudorotaxane, which should be of characteristic of the efficient polymer reactions progressing in a processive mode.

Keywords: Intermolecular Hydrosilylation; Intramolecular Hydroamination; Macrocycle Metal Complex; Polymer Reaction; Pseudorotaxane Intermediate.