Synthesis of aryl-substituted polyisobutylenes as precursors for ligands for greener, phase-selectively soluble catalysts

Abstract

General synthetic approaches to functional derivatives of polyisobutylene (PIB) that contain arene groups that can be used as catalysts or as precursors to catalyst ligands are discussed. The emphasis is on reactions that use commercially available terminally functionalized PIB derivatives as starting materials. Both successful and unsuccessful electrophilic aromatic substitution processes are described, and potential problems of this process and ways to circumvent the problem of depolymerization of the intermediate polyisobutyl cation in substitutions of less reactive arenes are detailed. Examples that lead to polyisobutyl-containing arenes that are known and potentially useful as ligands or ligand precursors for greener homogeneous catalysts that are phase-selectively soluble and recoverable in heptane are emphasized.