Syndioselective Polymerization of Vinylnaphthalene

Abstract

Coordination polymerizations of 1‐vinylnaphthalene (1VN), 2‐vinylnaphthalene (2VN) and 6‐methoxy‐2‐vinylnaphthalene (MVN) are carried out at room temperature by using the half‐sandwich scandium precursor FluSiMe3Sc(CH2SiMe3)2(THF) (1) and the constrained geometry configuration rare‐earth metal precursors FluCH2PyLn(CH2SiMe3)2(THF)n [Flu = C13H8, Py = C5H4N; Ln = Sc (2a), n = 0; Ln = Lu (2b), Y(2c), n = 1]. Atactic poly(1VN) and perfect syndiotactic poly(2VN) and poly(MVN) are produced by precursors 2a‐2c in a controlled way. Treatment of poly(MVN) with boron tribromide at −20 °C provides a syndiotactic poly(6‐hydroxy‐2‐vinylnaphthalene).

Syndiospecific Polymerization of o-Methoxystyrene and Its Silyloxy or Fluorine-Substituted Derivatives by HNC-Ligated Scandium Catalysts: Synthesis of Ultrahigh-Molecular-Weight Functionalized Polymers

“…The coordination (co)­polymerization of polar olefins to prepare high functional polyolefins having superior surface properties, adhesion properties, and compatibility with other types of materials has always been a challenging and high-profile issue in academia and industry. − The most serious difficulty lies in the fact that the high oxyphilic early transition metal catalysts can be easily poisoned by polar olefins because the stronger Lewis basic heteroatom groups of polar olefins have more preferential coordination ability than the weaker Lewis basic double bond to the strong Lewis acidic metal centers. − Subsequently, the low oxyphilic late transition metal catalysts, which are more tolerant of heteroatom functionalities in the monomer and the polymer, have ascended on the history stage and gradually began to open up new areas for the coordination (co)­polymerization of polar olefins such as polar norbornene, acrylates, vinyl ethers, vinyl acetate, vinyl halides, acrylonitrile, CO, etc. − Recently, a significant breakthrough in the coordination (co)­polymerization of polar olefins has been made by the high oxyphilic rare-earth metal catalysts. − Activated by a catalytically equimolar amount of cocatalyst borate and/or an excess of AlR 3 , rare-earth metal alkyl cations [LLnR] + generated from a series of rare-earth metal dialkyl complexes LLnR 2 L' n (Ln is a rare earth metal center, L is a negative monovalent multi-dentate supporting ligand, R is a negative monovalent alkyl ligand, L' n is a neutral ligand like tetrahydrofuran (THF) solvent molecules with a number in the range of 0–2) exhibit high activities and stereoselectivities in the coordination (co)...…”

Syndioselective Coordination (Co)Polymerization of Alkyne-Substituted Styrenes Using Rare-Earth Metal Catalysts

“…For example, the isoselective polymerization of ortho -methoxystyrene using β-diketiminato rare-earth metal catalysts has been achieved via a monomer self-activation mechanism . Subsequently, syndioselective (co)­polymerizations of alkoxystyrene, methylthiostyrene, halogenated styrene, vinylnaphthalene, etc., have been successfully realized using rare-earth metal catalysts. − Nevertheless, the polar groups of styrene derivatives and the resulting products still have a certain negative effect on polymerization activity. Thus, to efficiently incorporate different functional groups into polymers using transition-metal catalysts is still a challenging task. ,, Furthermore, stereoregulated polystyrenes containing functional groups are only available for a limited set of styrene derivatives, excluding those having strong polar groups…”