RAFT polymerization of isopropenyl boronate pinacol ester and subsequent terminal olefination: precise synthesis of poly(alkenyl boronate)s and evaluation of their thermal properties

Kanazawa, Tomoaki; Nishikawa, Tsuyoshi; Ouchi, Makoto

doi:10.1038/s41428-021-00498-8

Cited by 13 publications

(12 citation statements)

References 29 publications

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“…The glass transition temperature of poly‐ N ‐isopropenyloxycarbonyl‐L‐leucine methyl ester was 65 °C. The ability of isopropenyl boronate pinacol ester to serve as a monomer in radical polymerizations was established and exploited for the synthesis of polymers that are difficult to access using other polymerization techniques (Scheme 34, g) [131] . The boronyl pendants, which were directly attached to the polymer backbone, can be replaced with ‐OH or ‐NH 2 to yield poly(α‐methylvinylamine) or poly(α‐methylvinylalcohol), which has been inaccessible by conventional synthetic methods.…”

Section: Reactivitymentioning

confidence: 99%

Isopropenyl Esters (iPEs) in Green Organic Synthesis

Rigo

Masters

Maschmeyer

et al. 2022

Chemistry A European J

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The need for greener compounds able to replace conventional ones with similar reactivity is crucial for the development of sustainable chemistry. Isopropenyl esters (iPEs) represent one eco-friendly alternative to acyl halides and anhydrides. This review provides a comprehensive overview of the preparation methodologies and reported synthetic applications of iPEs and, in particular, of isopropenyl acetate (iPAc). Intriguingly, the presence of a C=C double bond adjacent to the ester functionality makes iPEs appealing in different chemoselective organic synthesis transformations. For instance, the acyl moiety is suitable for transesterification reactions in presence of different heteroatom-based nucleo-philes (CÀ , OÀ , NÀ , SÀ , SeÀ ); these reactions are irreversible thanks to the formation of acetone, obtained upon keto-enol tautomerization of the prop-1-en-2-ol (isopropenyl) leaving group. Similarly, the unsaturation contained in the isopropenyl synthon could be selectively exploited in organic synthesis for electrophilic and/or radical additions as well as in metal-catalyzed cross-coupling reactions. To conclude, iPEs recently found major interest in the direct modification of biomass (i.e. lignin or cellulose) and in the implementation of tandem reactions of esterification-acetalization by exploiting the co-formation of acetone during the reaction.

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Section: Reactivitymentioning

confidence: 99%

Isopropenyl Esters (iPEs) in Green Organic Synthesis

Rigo

Masters

Maschmeyer

et al. 2022

Chemistry A European J

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“…17,19 Ouchi and Nishikawa have described isopropenyl pinacol boronate ester (IPBpin) as an electron-rich monomer 22 that copolymerizes with St (r 1 (St) = 1.41; r 2 (IPBpin) = 0.085) and can be oxidatively converted to methyl vinyl alcohol residues. 23,24 In 2021, Ouchi and Nishikawa reported vinyl pinacol boronate ester (VBpin)− styrene copolymerizations (r 1 (St) = 3.77; r 2 (VBpin) = 0.25) and postpolymerization organoborane oxidation. 25 Very recently, Chen et al reported free-radical polymerization of gem-trifluoromethyl/boron-functionalized monomers.…”

Section: ■ Introductionmentioning

confidence: 99%

“…We reported BN 2-vinylnaphthalene (BN2VN) as an aromatic , monomer that readily copolymerizes with activated monomers like 2-vinylnaphthalene, styrene, − and methyl methacrylate . BN2VN’s aromaticity results in a close agreement in reactivity ratios with styrene (St) during radical polymerization ( r 1 (St) = 2.30; r 2 (BN2VN) = 0.423) and compatibility with coordination polymerization catalysts. , Organoborane oxidation under aqueous or organic conditions afforded vinyl alcohol (VA) (co)polymers. , Ouchi and Nishikawa have described isopropenyl pinacol boronate ester (IPBpin) as an electron-rich monomer that copolymerizes with St ( r 1 (St) = 1.41; r 2 (IPBpin) = 0.085) and can be oxidatively converted to methyl vinyl alcohol residues. , In 2021, Ouchi and Nishikawa reported vinyl pinacol boronate ester (VBpin)–styrene copolymerizations ( r 1 (St) = 3.77; r 2 (VBpin) = 0.25) and postpolymerization organoborane oxidation . Very recently, Chen et al reported free-radical polymerization of gem-trifluoromethyl/boron-functionalized monomers …”

Section: Introductionmentioning

confidence: 99%

Characterization of Styrene–Vinyl Alcohol Copolymers by CP-MAS NMR Spectroscopy

Catazaro

Jiang

et al. 2022

Macromolecules

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The first solid-state characterization of statistical copolymers of vinyl alcohol and styrene (poly(VA-stat-St)) by cross-polarization magic angle spinning (CP-MAS) spectroscopy is described. Poly(VA-stat-St) is not available from the traditional feedstocks styrene (St) and vinyl acetate (VAc) due to a mismatch in reactivity ratios. BN 2-vinylnaphthalene (BN2VN) is a synthetic solution to this challenge as it copolymerizes with activated monomers (e.g., styrene, methyl methacrylate), and the BN naphthalene side chain can be oxidatively converted to hydroxyl (−OH) side chains. While high levels of BN2VN incorporation are readily achieved (e.g., >75 mol % BN2VN), prior work has identified that poly(VA-stat-St) is poorly soluble in organic solvents when the molar fraction of VA exceeds 0.50, presumably due to the hydrophilic character of the hydroxyl group as well as possible interchain hydrogen bonding. Circumventing this solubility challenge, we describe quantitative solid-state 13 C CP-MAS spectra demonstrating high conversion (85−99%) of poly(BN2VN-stat-St) to poly(VA-stat-St). 11 B CP-MAS confirmed the removal of organoborane functional groups.

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“…Recently, our group revealed the radical (co)polymerization ability of alkenylboronic acid pinacol ester. 7 The boron pendant directly attached to the backbone was transformable into other elements, and the transformation enabled the synthesis of conventionally inaccessible (co)polymers. A hypothesis is that the C–B bond might be useful as the trigger for the backbone degradation because the C–B bond is known to undergo homolytic cleavage via oxidation by a metal oxidant, 8 a photocatalyst, 8 b or electrochemical reaction.…”

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confidence: 99%