ZWITTERIONIC CATALYSTS FOR (TRANS)ESTERIFICATION: APPLICATION IN FLUOROINDOLE-DERIVATIVES AND BIODIESEL SYNTHESIS
申请人:The Chinese University of Hong Kong
公开号:US20210023539A1
公开(公告)日:2021-01-28
An amide/iminium zwitterion catalyst has a catalyst pocket size that promotes transesterification and dehydrative esterification. The amide/iminium zwitterions are easily prepared by reacting aziridines with aminopyridines. The reaction can be applied a wide variety of esterification processes including the large-scale synthesis of biodiesel. The amide/iminium zwitterions allow the avoidance of strongly basic or acidic condition and avoidance of metal contamination in the products. Reactions are carried out at ambient or only modestly elevated temperatures. The amide/iminium zwitterion catalyst is easily recycled and reactions proceed in high to quantitative yields.
Comblike, surfactant polymers for changing the surface properties of biomaterials are provided. Such surfactant polymers comprise a polymeric backbone of repeating monomeric units having functional groups for coupling with side chains, a plurality of hydrophobic side chains linked to said backbone via the functional groups, and a plurality of hydrophilic side chains linked to said backbone via the functional groups. The hydrophobic side chains comprise an alkyl group comprising from 2 to 18 methylene groups. The alkyl groups are linked to the polymeric backbone through ester linkages, secondary amine linkages, or, preferably, amide linkages. The hydrophilic side chain is selected from the group consisting of: a neutral oligosaccharide, which, preferably, has weight average molecular weight of less than 7000; a charged oligosaccharide, preferably a negatively charged oligosaccharide having a weight average molecular weight of less than 10,000; an oligopeptide of from about 3 to about 30 amino acid residues, said oligopeptide having an amino acid sequence which interacts with protein receptors on the surface of cells; and combinations thereof. Methods of making the surfactant polymers and using the surfactant polymers to alter the surface properties of a biomaterial are also provided.
Aromatic ethers and process for producing aromatic ethers
申请人:——
公开号:US20040181099A1
公开(公告)日:2004-09-16
According to a production process, aromatic ethers are producible by reacting phenols with an oxirane compound with use of an anion exchange resin as a catalyst. According to another production process, aromatic ethers having an alcoholic hydroxyl group are producible by a crystallization-purification step of using a solvent having a solubility parameter ranging from 7.5 to 12.5 for purification by crystallization. Further, according to still another production process, producible are aromatic ethers having an alcoholic hydroxyl group, wherein the content of a metal in the aromatic ethers is less than 100 ppm by mass, and the content of a halogen element in the aromatic ethers is less than 100 ppm by mass.
Pentacyanocyclopentadienide (PCCp−), a stable π‐electronic anion, provided various ion‐pairing assemblies in combination with various cations. PCCp−‐based assemblies exist as single crystals and mesophases owing to interionic interactions with π‐electronic and aliphatic cations with a variety of geometries, substituents, and electronic structures. Single‐crystal X‐ray analysis revealed that PCCp− formed
A method of producing an organosilicon compound includes substituting at least an OR
1
group of a compound shown by the following general formula (1) to obtain a compound shown by the following general formula (2),
Si(OR
1
)
3-m
Y
1
m
—R
2
—Si(OR
3
)
3-n
Y
2
n
(1)
Si(OR
4
)
3-m
Y
1
m
—R
2
—Si(OR
4
)
3-n
Y
2
n
(2).