Cationic ring-opening polymerization of ?-thionocaprolactone: Selective formation of polythioester

Sanda, Fumio; Jirakanjana, Duangjai; Hitomi, Masakatsu; Endō, Takeshi

doi:10.1002/1099-0518(20001115)38:22<4057::aid-pola50>3.0.co;2-8

Cited by 33 publications

(24 citation statements)

References 10 publications

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“…9 The other S-substituted caprolactone, ε-thionocaprolactone (tnCL, Scheme 1), has been the subject of only two published reports. 10,11 Under cationic polymerization conditions, the ROP of tnCL proceeds with quantitative inversion of substitution at the thionoester to generate the same poly(thiocaprolactone) previously reported by Overberger and our group. 9,13,14 The anionic ROP of tnCL from alkyllithium reagents retains the S-carbonyl substitution, but reaction control suffers, and this method does not allow for M n control, copolymerization, or end group selection.…”

Section: Introductionmentioning

confidence: 66%

Controlled Organocatalytic Ring-Opening Polymerization of ε-Thionocaprolactone

Datta

Kiesewetter

2016

Macromolecules

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For the first time, the controlled ring-opening polymerization (ROP) of ε-thionocaprolactone (tnCL) is conducted. The organocatalytic ROP of tnCL occurs without carbonyl scrambling, leading to homopoly(ε-thionocaprolactone) (PtnCL). The ROP by base catalysts alone is proposed to proceed via a nucleophilic mechanism, while the addition of an H-bond donating thiourea (TU) is shown to provide excellent reaction control. The increased reaction control provided by the TU occurs in the virtual absence of binding between tnCL and TU, and a mechanistic account for this observation is discussed. The monomer ring strain is measured and found to be similar to δ-valerolactone (VL). Copolymers with VL are synthesized, and the resulting analysis of the copolymer materials properties provides the only known physical characterizations of poly(thio(no)ester-co-ester)s.

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Section: Introductionmentioning

confidence: 66%

Controlled Organocatalytic Ring-Opening Polymerization of ε-Thionocaprolactone

Datta

Kiesewetter

2016

Macromolecules

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“…A one‐step method for PTE synthesis is the ring‐opening polymerization of the respective thiolactones (Figure 3 (4)). Anionic polymerization of ε ‐thionocaprolactone has been achieved by the use of Grignard reagents or methyllithium as initiators, whereas catalysts like boron trifluoride etherate and methyl trifluoromethanesulfonate have been identified to generate cationic polymerization 26,27. Recently, ring‐opening polycondensations of 2‐stanna‐1,3‐dithiacycloalkanes with dicarboxylic acid chlorides have been reported (Figure 3 (5)) 28,29.…”

Section: Synthetic Ptesmentioning

confidence: 99%

Microbial Polythioesters

Lütke‐Eversloh

Steinbüchel

2004

Macromolecular Bioscience

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This feature article describes the current knowledge on biosynthesis of polythioesters (PTEs), which are exclusively accumulated by microorganisms capable to synthesize the well-known polyhydroxyalkanoates (PHAs). Two bacterial PTE biosynthesis systems are discussed, both are depending on the cultivation conditions and appropriate feeding regimes. The first system comprises the production of PTE copolymers by Ralstonia eutropha, and the second system has been established in recombinant Escherichia coli to produce PTE homopolymers. Furthermore, synthetic PTEs and other related sulfur containing biopolymers are briefly summarized.

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“…11 In 2016, our group disclosed the H-bond-mediated ROP of thionocaprolactone (tnCL). 11 Versus earlier studies, 15,16 the key advance with this report was that the H-bond-mediated organocatalysts facilitate the retention of the S/O substitution during the ROP. This is vital for accessing the altered materials properties of thionolactones (versus thiolactones), and the organocatalytic methods allow for the synthesis of copolymers.…”

Section: Introductionmentioning

confidence: 79%