KCS

Several new ligand and reagent developments relevant to polymerization catalysis will be presented and discussed. Treatment of acetonitrile with base and a phosphorus halide gives rise to the formation of the doubly phosphorylated organic nitrile. Staudinger reaction transforms this to the double phosphinimine system that serves as a basis for the preparation of a series of transition metal complexes. Some of these systems are olefin polymerization catalysts that use the pendent nitrile functionality for electronic modification. We have developed a straightforward synthetic pathway to functionalized [3]ferrocenophane systems by means of a variant of the Mannich reaction. The resulting ferrocenophanes have served as frameworks for the preparation of a variety of chelate bis(phosphine)ligands for Pd-catalyzed alternating CO/alkene copolymerization reactions. High asymmetric induction is achieved in alt-CO/propene copolymer formation by using highly enantiomerically enriched ligands. We also developed a series of ferrocene derived chelate sulfonate/phosphine Pd-catalyst systems for non-alternating CO/ethene copolymerization and we will present ferrocene analogues of the salicylaldimine metal catalyst family that are active non-metallocene catalysts for ethene polymerization reactions. Eventually, if time allows, a unique synthesis of a new family of persistent nitroxide radicals will be presented that is based on our recent frustrated Lewis pair chemistry. Such new radicals and their diamagnetic derivatives will be of great interest in radical polymerization catalysis.