Polymers from sugars and isothiocyanates: ring-opening copolymerization of a<scp>d</scp>-xylose anhydrosugar oxetane

Clark, Ella F.; Kociok‐Köhn, Gabriele; Davidson, Matthew G.; Buchard, Antoine

doi:10.1039/d3py00443k

“…The observation of a resonance at 157 ppm in the 13 C-{ 1 H} NMR spectrum is in line with the formation of a heterocarbonate (see resonance 1 in Figure 1(b)), corresponding to a polymer with À (CH 2 ) 3 À OÀ C(=NPh)À SÀ linkages (abbreviated as ONS). [34] The formation of a À C=NÀ group is further supported by IR spectroscopy with a characteristic band for the CÀ N-stretching vibration at ṽ = 1630 cm À 1 (see Figure 1(c)). In addition, small aliphatic ester…”

Section: Resultsmentioning

confidence: 79%

Easy Synthetic Access to High‐Melting Sulfurated Copolymers and their Self‐Assembling Diblock Copolymers from Phenylisothiocyanate and Oxetane

Stephan,

Olmedo‐Martínez,

Fornacon‐Wood

et al. 2024

Angew Chem Int Ed

0

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Although sulfurated polymers promise unique properties, their controlled synthesis, particularly when it comes to complex and functional architectures, remains challenging. Here, we show that the copolymerization of oxetane and phenyl isothiocyanate quantitatively yields polythioimidocarbonates as a new class of sulfur containing polymer, with narrow molecular weight distributions (Mn = 5–80 kg/mol with Đ ≤ 1.2; Mn,max = 124 kg/mol) and high melting points of up to 181 ºC. The method tolerates different substituent patterns on both the oxetane and the isothiocyanate. Self‐nucleation experiments reveal that π‐stacking of phenyl substituents, the presence of unsubstituted polymer backbones, and the kinetically controlled linkage selectivity are key factors in maximising melting points. The increased tolerance to macro‐chain transfer agents and the controlled propagation allows the synthesis of double crystalline and amphiphilic block copolymers, which can be assembled into micellar‐ and worm‐like structures with amorphous cores in water. While in ethanol, crystallization driven self‐assembly gives cylindrical micelles or platelets.

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“…Furthermore, its metal catalytic synthesis method exhibits low activity with a turnover of frequency (TOF) of around 10 h –1 and also causes a brown color (Scheme ) and unpleasant metal residues of the poly(thiocarbonate). Additionally, the xylose oxetane has also been used in homopolymerization and other copolymerizations, like with CS 2 , CO 2 , cyclic anhydrides, or isothiocyanates . Xu and co-workers reported the alternating copolymerization of OX and various cyclic anhydrides by the use of a phosphazene base combined with triethyl borane (TEB), yielding several polyesters with good thermal stability …”

Section: Introductionmentioning

confidence: 99%

“…Additionally, the xylose oxetane has also been used in homopolymerization 46 and other copolymerizations, like with CS 2 , 47 CO 2 , 48 cyclic anhydrides, 49 or isothiocyanates. 50 use of a phosphazene base combined with triethyl borane (TEB), yielding several polyesters with good thermal stability. 49 Here, we use alkyl borane to replace (salen)CrCl as an organic Lewis acid for the copolymerization to yield metal-free poly(thiocarbonate) with complete XO-alt-COS repeating units (Scheme 1).…”

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confidence: 99%

Organocatalytic Synthesis of Poly(thiocarbonate) from Xylose and Carbonyl Sulfide

Feng,

Liu

et al. 2024

Macromolecules

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Facile synthesis of sulfur-containing polymers from renewable chemicals or the waste of petrochemical resources remains a grand challenge. Here, we report organocatalytic alternating copolymerization of carbonyl sulfide (COS) and D-xylose oxetane (XO) to produce poly(thiocarbonate). COS is industrially released as a waste gas, while XO is synthesized from biorenewable xylose with an E factor of 2.31 and an atom economy of 30%. The commercially available binary organocatalyst system consists of alkyl borane (as a Lewis acid) and a quaternary ammonium salt (as an initiator). Density functional theory calculations suggest that the Lewis acid of borane can activate XO and stabilize the growing anion. The catalyst system exhibits high activity with turnover frequencies of up to 70 h −1 at 25 °C, affording poly(thiocarbonate) with a welldefined structure, complete alternating sequence, >99% chemoselectivity, and regioregular polymer backbone composed of head-to-tail linkages. Terpolymerization of XO, propylene oxide, and COS yields a series of poly(thiocarbonate) with a largely tunable T g ranging from 26 to 138 °C.

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“…[31,32] However, both ROCOP reactions result in polymers with a broadened molecular weight distribution (Đ > 1.5) which is also observed for many other ring-opening polymerisations of sulfurated monomers. [33][34][35][36][37][38][39] This suggests the occurrence of side reactions alongside chain propagation, such as chainend coupling and transesterification. [40] These side-reactions can reduce the resulting molecular weights, and can complicate the application of the polymerisations in the synthesis of more complex architectures, such as block copolymers.…”

Section: Introductionmentioning

confidence: 99%

Easy Synthetic Access to High‐Melting Sulfurated Copolymers and their Self‐Assembling Diblock Copolymers from Phenylisothiocyanate and Oxetane

Stephan,

Olmedo‐Martínez,

Fornacon‐Wood

et al. 2024

Angewandte Chemie

0

View full text Add to dashboard Cite

Although sulfurated polymers promise unique properties, their controlled synthesis, particularly when it comes to complex and functional architectures, remains challenging. Here, we show that the copolymerization of oxetane and phenyl isothiocyanate quantitatively yields polythioimidocarbonates as a new class of sulfur containing polymer, with narrow molecular weight distributions (Mn = 5–80 kg/mol with Đ ≤ 1.2; Mn,max = 124 kg/mol) and high melting points of up to 181 ºC. The method tolerates different substituent patterns on both the oxetane and the isothiocyanate. Self‐nucleation experiments reveal that π‐stacking of phenyl substituents, the presence of unsubstituted polymer backbones, and the kinetically controlled linkage selectivity are key factors in maximising melting points. The increased tolerance to macro‐chain transfer agents and the controlled propagation allows the synthesis of double crystalline and amphiphilic block copolymers, which can be assembled into micellar‐ and worm‐like structures with amorphous cores in water. While in ethanol, crystallization driven self‐assembly gives cylindrical micelles or platelets.

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Polymers from sugars and isothiocyanates: ring-opening copolymerization of ad-xylose anhydrosugar oxetane

Abstract: A D-Xylose 3,5 anyhydrosugar (D-Ox) has been applied in the ring-opening copolymerisation (ROCOP) with isothiocyanates to form alternating AB-type copolymers with imidothiocarbonate linkages (Mn ≥ 34,900 g mol−1). Catalysed by...

Cited by 7 publications

References 47 publications

Easy Synthetic Access to High‐Melting Sulfurated Copolymers and their Self‐Assembling Diblock Copolymers from Phenylisothiocyanate and Oxetane

Easy Synthetic Access to High‐Melting Sulfurated Copolymers and their Self‐Assembling Diblock Copolymers from Phenylisothiocyanate and Oxetane

Organocatalytic Synthesis of Poly(thiocarbonate) from Xylose and Carbonyl Sulfide

Easy Synthetic Access to High‐Melting Sulfurated Copolymers and their Self‐Assembling Diblock Copolymers from Phenylisothiocyanate and Oxetane

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