Highly syndioselective coordination (co)polymerization of isopropenylstyrene

Abstract

Coordination (co)polymerization of para-isopropenylstyrene (pIPSt) and meta-isopropenylstyrene (mIPSt), initiated by scandium (Sc) based catalysts, afforded new type of products, bearing pendant isopropenyl groups with perfect syndiotacity (rrrr > 99%).

Syndiospecific Coordination Polymerization of Si‐H‐Containing Styrenes Catalyzed by Scandium Complex and Synthesis of Styrene‐Based Triblock Copolymers

“…But the direct polymerization of such styrene derivatives is still limited to the combination of polar groups with specific catalyst systems, because the strong Lewis acid–base interaction between polar groups and catalyst centers extremely restricted polymerization stereoselectivity and activity. On the contrary, through the direct polymerization, the introduction of reactive groups like methyl, borane, and alkenyl into sPS can appropriately overcome the effect of polar groups on polymerization stereoselectivity and activity. Meanwhile, these reactive groups were facilely converted to diversified functional groups via effective chemical reactions to produce functional sPS‐based materials.…”

“…In spite of the abovementioned advances in functionalization of sPS, however, in the synthesis of functional styrene and styrene copolymer, almost all functional styrenes are always distributed along the sPS backbones in a random manner to give random copolymers, in which 5–10 mol% of functional styrene insertion would damage the crystallization of sPS and cause the loss of melting point of the copolymer . In order to solve the problem, the block copolymerization of functional styrene with styrene becomes more and more crucial.…”

“…Therefore, the investigation of functionalized sPS containing reactive groups will be of important significance in academic and industrial community.In spite of the abovementioned advances in functionalization of sPS, however, in the synthesis of functional styrene and styrene copolymer, almost all functional styrenes are always distributed along the sPS backbones in a random manner to give random copolymers, in which 5-10 mol% of functional styrene insertion would damage the crystallization of sPS and cause the loss of melting point of the copolymer. [12,13,[15][16][17] In order to solve the problem, the block copolymerization of functional styrene with styrene becomes more and more crucial. So far, the reports on sPS block copolymers mainly concentrate on diblock or multi-block copolymers [18][19][20][21][22] obtained by one-step monomer feeding process via coordination polymerization, basing on the different properties (for example, the reactivity) of monomers.…”

Stereoselective Polymerization of an Aromatic Vinyl Monomer to Access Highly Syndiotactic Poly(vinyl alcohol)

“…[ 17,18 ] We wish to solve this problem in an alternative method by employing vinyl monomers containing nonpolar but “reactive” substituent to perform stereoselective polymerization, and then transferring the substituent into other functional groups through postpolymerization modification. [ 19,20 ] Vinyl compounds bearing boraza (BN) aromatic ring are such monomers where the amino nitrogen with high coordinative capacity is well protected by the single intramolecular boron atom instead of a bulky substituent; boron atom in the aromatic ring can be easily transformed into other group without racemizing the potential chirality of the adjacent carbon atom, thus the stereoregularity of resulting polymers is remained after postpolymerization modification. A series of BN containing monomers such as BN‐styrene and BN‐vinylbiphenyl are reported to polymerize via RAFT mechanism.…”

Syndioselective Polymerization of Vinylnaphthalene

“…[53] Recently, we found that rare-earth metal catalysts supported by pyridyl methyl fluorenyl ligand demonstrated their superiority on selective and controlled coordination polymerization of styrene derivatives bearing various electron-donating/ withdrawing substituents. [34,37,38,[54][55][56][57][58][59] With the help of these powerful constrained geometry configuration (CGC) catalysts, we successfully synthesized a series of high syndiotactic polystyrene derivatives such as poly(methoxystyrene), poly(4-Methylthiostyrene), poly(4-fluorostyrene) etc. [34,35,37,38,41] In this contribution, we report that coordination polymerizations of 1VN, 2VN, and MVN were carried out by using the halfsandwich scandium precursor 1 and the CGC rare-earth metal precursors 2a-2c (Figure 1).…”