Polystyrene‐Supported 1,5,7‐Triazabicyclo[4.4.0]dec‐5‐ene as an Efficient and Reusable Catalyst for the Thiolysis of 1,2‐Epoxides under Solvent‐Free Conditions.

Fringuelli, Francesco; Pizzo, Ferdinando; Vittoriani, Carla; Vaccaro, Luigi

doi:10.1002/chin.200625098

Cited by 2 publications

(2 citation statements)

References 1 publication

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“…It was assumed that the ring-opening reaction of PO took place prior by nucleophilic attack from 1-propylthiol, affording 1-(n-propyl)thiopropan-2-ol [C 3 H 7 S−CH 2 CH(CH 3 )OH], which acted as the real chain transfer agent for the copolymerization due to the relatively high reactivity of 1-propylthiol with PO. 35 As an analogue of H 2 O, hydrogen sulfide (H 2 S) was used as CTA for the COS/PO copolymerization. H 2 S was prepared by the reaction of FeS and sulfuric acid, dried by passing through a P 2 O 5 column, and bubbled into the mixture of PO and the catalyst for 15 min before the addition of COS. As was expected, DTC units were not observed, but a thioether linkage (Figures 3B and 4B, Figure S15) was noted in the final copolymer resulting from the fast reaction of H 2 S with PO to produce bis(2hydroxypropyl) sulfide as the chain transfer agent, similar to the above-mentioned instance with 1-propylthiol.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Mechanistic Study of Regio-Defects in the Copolymerization of Propylene Oxide/Carbonyl Sulfide Catalyzed by (Salen)CrX Complexes

Duan

Luo

et al. 2017

Macromolecules

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Small quantities of regio-defects in a regio-/stereoregular polymer weaken its tacticity and properties. This work clarified the origin of the regio-defect in the process of synthesizing poly(monothiocarbonate) through the copolymerization of propylene oxide (PO) and carbonyl sulfide (COS) catalyzed by a (salen)CrCl complex accompanied by bis(triphenylphosphoranylidene)ammonium chloride ([PPN]Cl). Quantitative characterization results from the MALDI-TOF-MS and 1H (13C) NMR spectroscopy suggested that the chain transfer reaction resulted in the regio-defect in the final copolymer, i.e., tail-to-tail (T–T) diad and dithiocarbonate (DTC) unit. The chain transferring to water in the reaction system led to the production of a (salen)Cr–OH intermediate, which initiated the copolymerization via either attacking PO first to result in formation of a T–T diad or first activating COS to produce mercapto (−SH) end-capped dormant chains via decarboxylation, thus generating a DTC unit in the final product through another chain transfer reaction and regrowth of the chain. The content of regio-defect in the final copolymer was directly related to the water content in the system. It is essential to reduce the regio-defect for an immortal COS/PO copolymerization reaction by eliminating trace amounts of water. We also demonstrated the application of α-OH, ω-OH poly(propylene monothiocarbonate) for synthesizing a well-defined ABA triblock copolymer, polystyrene-block-poly(propylene monothiocarbonate)-block-polystyrene (PS-b-PPMTC-b-PS), with a M n of 10 800 g/mol and a PDI of 1.08 via an atom transfer radical polymerization (ATRP) method.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Mechanistic Study of Regio-Defects in the Copolymerization of Propylene Oxide/Carbonyl Sulfide Catalyzed by (Salen)CrX Complexes

Duan

Luo

et al. 2017

Macromolecules

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“…The thiol group tends to lose the hydrogen ion and form a negative ion of mercaptan, which can be stabilized by the strong electrophilic effect of the adjacent substituents. 41 In other words, the more acidic thiol group will be more reactive. It has been observed that aromatic thiol groups with low pK a values can react more easily with epoxy groups than alkanethiol groups with high pK a values.…”

Section: Synthesis and Characterization Of The Membranementioning

confidence: 99%

Surface Modification of Cellulose Membranes To Prepare a High-Capacity Membrane Adsorber for Monoclonal Antibody Purification via Hydrophobic Charge-Induction Chromatography

Yao

Yang

et al. 2018

Ind. Eng. Chem. Res.

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Hydrophobic charge-induction chromatography (HCIC) has emerged as an efficient method for antibody purification, but traditional packed-bed chromatography continues to suffer from high pressure drop and low transport efficiency. A versatile surface modification method is proposed to prepare HCIC membrane adsorbers. We first modified a commercial regenerated cellulose (RC) membrane by the cationic ring-opening polymerization (CROP) of diethylene glycol diglycidyl ether (DEGDE), producing the RC-g-PDEGDE membrane, which was then modified by the ringopening reaction of an epoxy group with a sulfydryl group in four mercaptoheterocyclic ligands. Bovine serum albumin (BSA) and human immunoglobulin G (IgG) were used as model contaminant and antibody, respectively. The highest ligand density achieved is 370 mmol/L, and the static and dynamic adsorption capacities of IgG reached 195 and 65 mg/mL, respectively. The high dynamic capacity and IgG recovery (96%) are believed to benefit from the branched structure of DEGDE and convective transport in membrane pores.

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Polystyrene‐Supported 1,5,7‐Triazabicyclo[4.4.0]dec‐5‐ene as an Efficient and Reusable Catalyst for the Thiolysis of 1,2‐Epoxides under Solvent‐Free Conditions.

Cited by 2 publications

References 1 publication

Mechanistic Study of Regio-Defects in the Copolymerization of Propylene Oxide/Carbonyl Sulfide Catalyzed by (Salen)CrX Complexes

Mechanistic Study of Regio-Defects in the Copolymerization of Propylene Oxide/Carbonyl Sulfide Catalyzed by (Salen)CrX Complexes

Surface Modification of Cellulose Membranes To Prepare a High-Capacity Membrane Adsorber for Monoclonal Antibody Purification via Hydrophobic Charge-Induction Chromatography

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