Addition of carbon dioxide to allyl glycidyl ether using ionic liquids catalysts

The addition of carbon dioxide to allyl glycidyl ether (AGE) was investigated without using any solvent in the presence of ionic liquid as catalyst. Ionic liquids based on 1-ethyl-3-methylimidazolium (EMIm), 1-butyl-3-methylimidazolium (BMIm), and 1-hexyl-3-methylimidazolium (HMIm) with different anions such as Cl⁻, BF₄⁻, PF₆⁻ were used as catalysts. The reaction was performed in a 50 mL stainless steel autoclave. The conversion of allyl glycidyl ether was affected by the structure of imidazolium salt ionic liquids; the one with the cation of bulkier alkyl chain length and with more nucleophilic anion showed better reactivity. Reaction temperature and carbon dioxide pressure enhanced the addition of carbon dioxide to AGE.     

Newer synthetic approaches to surfactants, lipids, and related compounds based on C-3 building blocks: Recent advances related to fatty chemistry

Many lipids derived from natural sources are based on the glycerin molecule. Synthetically alkyl glycidyl ether can be used as a C-3 building block for lipid molecules as well as alkyl glyceryl ether. Several glycidyl and glyceryl ethers have been studied as C-3 synthetic building blocks for lipids used in surfactants/emulsifiers, cosmetics, or toiletries. From an environmental viewpoint, several surfactants and detergents have been modified by using epichlorohydrin or glycerides as C-3 building blocks to have higher performance or biodegradability. Recently, complex lipid molecules having special bioactivities have attracted attention among chemists. Glycidyl ether would be expected to be one of the synthetic building blocks for such complex lipids.     

Applications of phase-transfer catalytic reactions to fatty acids and their derivatives: Present state and future potential

Phase-transfer catalysts (PTC), which accelerate reactions between liquid(organic)-liquid(water) and liquidsolid heterogeneous states, have been investigated and developed. Several processes with PTC have succeeded in industrial processes involving fatty acids and their derivatives. For example, preparation of fatty alkyl glycidyl ethers, from which fatty alkyl glyceryl ethers and their derivatives can be obtained, has been carried out with PTC. However, some problems remain to be solved. For example, preparation of the fatty alkyl glycidyl ether by a PTC reaction was considered, but typical problems to be solved included: (i) how to reuse or recover the catalysts; (ii) how to control the heterogeneous reaction without obstacles to produce useful chemical materials; (iii) how to satisfy the environmental requirements for the catalysts; and (iv) are there more effective catalysts? We address these problems based on our own experiences with phase-transfer catalytic Williamson ether syntheses of fatty alkyl glycidyl ethers. Moreover, we describe recent developments in phase-transfer catalytic reactions related to oleochemistry, such as transition metal-catalyzed reactions of long-chain olefins in liquid(organic)-liquid(water) or liquid-solid heterogeneous states. Based on these results, we have considered the potential of PTC as a synthetic tool in oleochemistry.     

Star-Shaped Poly(furfuryl glycidyl ether)-Block-Poly(glyceryl glycerol ether) as an Efficient Agent for the Enhancement of Nifuratel Solubility and for the Formation of Injectable and Self-Healable Hydrogel Platforms for the Gynaecological Therapies

In this paper, we present novel well-defined unimolecular micelles constructed a on poly(furfuryl glycidyl ether) core and highly hydrophilic poly(glyceryl glycerol ether) shell, PFGE-b-PGGE. The copolymer was synthesized via anionic ring-opening polymerization of furfuryl glycidyl ether and (1,2-isopropylidene glyceryl) glycidyl ether, respectively. MTT assay revealed that the copolymer is non-cytotoxic against human cervical cancer endothelial (HeLa) cells. The copolymer thanks to furan moieties in its core is capable of encapsulation of nifuratel, a hydrophobic nitrofuran derivative, which is a drug applied in the gynaecology therapies that shows a broad antimicroorganism spectrum. The study shows high loading capacity of the copolymer, i.e., 146 mg of nifuratel per 1 g of copolymer. The load unimolecular micelles were characterized using DLS and TEM microscopy and compared with the reference glyceryl glycerol ether homopolymer sample. The presence of numerous 1,2-diol moieties in the shell of PFGE-b-PGG macromolecules enabled the formation of reversible cross-links with 2-acrylamidephenylboronic acid-based polyacrylamide. The obtained hydrogels were both injectable and self-healable, which was confirmed with a rheological study.     

Synthesis of amphiphilic poly(phthalazinone ether sulfone ketone)‐graft‐poly(ethylene glycol) graft copolymers via Williamson etherification

Amphiphilic graft copolymers consisting of poly(phthalazinone ether sulfone ketone) (PPESK) backbones and poly(ethylene glycol) (PEG) side chains were synthesized via reaction of chloromethylated PPESK (CMPPESK) with a sodium alkoxide of methoxyl PEG (PEG‐ ONa). The reactive precursor, CMPPESK, was prepared by the chloromethylation of PPESK with chloromethylether (CME) using concentrated H₂SO₄ as reaction medium. FTIR spectroscopy, ¹H‐NMR and Solid‐state ¹³C CP‐MAS NMR analysis confirmed the covalent linking of PEG with PPESK backbones. The PEG content in the graft copolymers from ¹H‐NMR analysis varied from 21.0 to 37.2 wt %, which was approximately in agreement with that calculated from TGA tests. The graft products have good solubility in many aprotic polar solvents and can be slightly swelled by water and ethanol, but water insoluble. Contact angle measurements revealed that the hydrophilicity of PPESK was significantly improved by the introduction of PEG graft chains, indicating the graft copolymer is a potential hydrophilic additive for PPESK membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.     

The catalyst layer containing sulfonated poly(ether ether ketone) as the electrode ionomer for polymer electrolyte fuel cells

The electrode ionomer is a key component of the catalyst layer and therefore the introduction of new electrode ionomer would have a significant effect on cell performance. To investigate the effect of sulfonated poly(ether ether ketone) (sPEEK) as the electrode ionomer, the catalyst layer was prepared using sPEEK ionomer and its physical properties such as pore structure and the hydrophobicity were examined. The electrochemical characteristics of the membrane and electrode assemblies employing sPEEK ionomer-based catalyst layer were also analyzed. Even though sPEEK ionomer-based catalyst layer showed lower ohmic resistance compared with Nafion ionomer-based catalyst layer, complete pore-filling of sPEEK into the primary pore caused reduction in reactive surface area of the catalyst and hindrance in gas transfer. In addition, the very low hydrophobicity of sPEEK ionomer-based catalyst layer deteriorated gas transfer due to an increased water flooding.     

Cholesterol as synthetic building blocks for artificial lipids with characteristic physical,chemical and biological properties

Cholesterol is one of the most widely distributed natural materials and has a unique chemical structure such as a steroid skeleton. Many types of chemical transformations of cholesterol functional groups have been developed. There is an interest in the derivatization of cholesterol and to introduce alkyl branched fatty acids into the molecule. These have found applications in the formulation of cosmetics and toiletries over the past few decades. An extraordinary interesting case is related to cholesteryl esters and their use in gene therapy delivery systems. These results can be attributed to their potential for forming cell‐mimic membranes, because cholesterol is the most important building block of living cell membranes. In terms of organic synthesis, cholesterol is a strategically useful material. A typical case is remote functionalization by chemical reactions or by biocatalysis. In the future, cholesterol should be considered as a key compound, a building block for the construction of artificial lipid‐like membranes by self‐assembly. Also, as cholesterol is one of the members of the fat and oil family, fat and oil chemists should study and develop cholesterol chemistry even further.