Facile End‐Functionalization of Poly(Quinolylene‐2,3‐Methylene) Using the Terminal Palladium Complex: Thiocarbonylation through Formation of an Acyl Palladium Complex at the Polymer Terminal

Abstract

AbstractThe end‐functionalization of poly(quinolylene‐2,3‐methylene)s (PQM) via thiocarbonylation is successfully achieved by forming an acyl palladium complex. The terminal palladium complex of the PQMs synthesized by living cyclocopolymerization of o‐allenylaryl isocyanide is quantitatively converted to a tractable acyl palladium complex through the carbon monoxide insertion into a palladium–carbon bond. The resulting acyl palladium complex exhibits high reactivity toward thiols, thereby enabling the introduction of various substituents at the ω‐chain end of PQM by selectively converting them to thioester groups. The one‐pot procedure enables the arbitrary control of both terminal structures of PQMs, including the synthesis of multi‐armed block copolymers and a triblock polymer. Additionally, the resulting thioester groups can serve as reactive sites and be converted into amide groups using amines. The new end‐functionalization method has the potential to be applied not only to the synthesis of PQM but also to other polymerization reactions using transition‐metal complexes, and can lead to a wide range of developments in polymer synthesis.