Critical approaches in the catalytic transformation of sugar isomerization and epimerization after Fischer-History,challenges,and prospects

The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date.

Iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc:Synthesis of α-acetoxy aryl ketones via a Michael-like addition process

A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.

Amine-functionalized metal organic framework@graphene oxide as filler in PAEK-containing carboxyl group membrane for ultrafiltration with ultra-high permeability and strong fouling resistance

Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.

Ketone bodies and inflammation modulation:A mini-review on ketogenic diet’s potential mechanisms in mood disorders

Mental disorders such as depression and anxiety inflict significant burdens on individuals and society.Commonly prescribed treatments often involve cognitive therapy and medications.However,for patients resistant to these conventional methods,alternative therapies like the Ketogenic Diet(KD)offer a promising avenue.KD and its key metabolite,β-hydroxybutyrate(BHB),have been hypothesized to alleviate mental disorders through antiinflammatory actions,a crucial pathway in the pathophysiology of depression.This mini-review examines 15 clinical trials exploring the influence of KD and BHB on inflammation and their potential roles in managing mental disorders.Both human and animal studies were scrutinized to elucidate possible cellular and molecular mechanisms.Out of the 15 trials,10 reported reduced levels of at least one inflammatory mediator or mRNA post KD or BHB treatment,while two observed an elevation in anti-inflammatory agents.These findings suggest that KD and BHB could modulate cellular inflammatory pathways,highlighting their potential for therapeutic application in mental disorders.

AusMed Brings Game-Changing Healthcare Innovations from Hong Kong,China to the World——An interview with Christine Yip,Founder and CEO of AusMed Global Limited

“As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expensive specialty equipment,we proudly introduce the world’s first-of-its-kind handheld breath ketone(BrAce)analyser,empowered by our patented disruptive photonic sensing technologies.These innovations are aimed at providing a more effective approach to managing diabetes and ketosis(fat metabolism),”said Christine Yip,founder and CEO of AusMed Global Limited,during a recent interview with China’s Foreign Trade magazine.

Copper-Catalyzed C-C(O)C Bond Cleavage of Monoalkylated β-Diketone: Synthesis of α,β-Unsaturated Ketones

A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K3PO4) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .

Solvent extraction of hafnium from thiocyanic acid medium in DIBK-TBP mixed system

A novel process for the separation of hafnium from thiocyanic acid medium using the mixture of diisobutyl ketone（DIBK） and tributyl phosphate（TBP） as the extractant was developed.This extraction process was investigated experimentally as a function of the amount of TBP added,acidity,zirconium and hafnium concentrations,salting-out agent,temperature,duration,respectively.The results show that hafnium is enriched in the organic layer and zirconium is in aqueous layer in DIBK-TBP system.Under the optimal technological conditions：TBP addition 20%（v/v）,aqueous phase acidity 3.0 mol/L,ammonium sulfate addition 0.8-1.25 mol/L,room temperature and extraction time 10 min,the separation factor of hafnium from zirconium is 9.3.

芳香聚芳醚酮大环化合物结构分析

Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment ionization peaks except for the molecular ion peak from the mass spectrum.The structure of macrocyclic dimmer was further affirmed by the NMR spectra through the analysis of chemical shifts.The MALDI-TOF MS combining with NMR technique was found an important tool to characterized Macrocyclic aromatic oligomers.

聚硫醚酮与聚苯硫醚的合成及热性能研究

聚硫醚酮;聚苯琉醚;合成;

Transformation of bio-derived acids into fuel-like alkanes via ketonic decarboxylation and hydrodeoxygenation： Design of multifunctional catalyst, kinetic and mechanistic aspects

The combination of a low cost source of Biofine＇s levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable compounds for transportation sector. The present review illustrates the development of different approaches to one–pot synthesis of fuel-like alkanes from lignocellulose derived carboxylic acids where particular focus is given to valeric acid consecutive decarboxylative coupling（ketonization） and ketone hydrodeoxygenation in a single reactor over one catalyst bed. The key factors that influence the catalytic performance on both ketonization and hydrodeoxygenation steps as well as their cross-influence will be clarified to provide insights for the design of more efficient catalysts for the one-pot transformation. Valeric acid is considered as a potential acid source from viewpoint of cost effectiveness and feasibility of such transformation with reasonable alkane yield. The both reaction mechanisms and kinetics will also be discussed to understand deeply how the selective C–C coupling and following C=O hydrogenation can be achieved.

Direct oxidation of the C_(sp3)-H bonds of N-heterocyclic compounds to give the corresponding ketones using a reusable heterogeneous MnO_x-N@C catalyst

Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catalytic system exhibited a broad substrate scope and excellent regi‐oselectivity, as well as being amenable to gram‐scale synthesis. This MnOx‐N@C catalyst also showed good reusability and was successfully recycled six times without any significant loss of activity.

Equilibrium and kinetic data of adsorption and separation for zirconium and hafnium onto MIBK extraction resin

The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations of zirconium and hafnium and temperature.The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm,and the Freundlich isotherm constants(KF) are 3.53 and 0.64 mg/g,respectively.The equilibrium data of zirconium also fit the Langmuir adsorption isotherm,and the saturation adsorption capacity(Qmax) and the Langmuir isotherm constant(KL)are 75.93 mg/g and-0.012 7 L/g,respectively.The obtained kinetic data of both zirconium and hafnium are found to fit the HO pseudo-second-order kinetic model,and the rate constants of pseudo-second-order equation(k2) are-0.019 and 0.41 g/(mg·min),respectively.Column tests show that the MIBK extraction resin could be used as efficient adsorbent material for separating hafnium from zirconium.

SYNTHESIS AND PROPERTIES OF NOVEL POLY(IMINO KETONE)S AS HIGH-PERFORMANCE POLYMERS

Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...

Study on the Removal of MIBK from Aqueous Solution by Vacuum Membrane Distillation

Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitably, which not only pollutes working conditions, but also affects the quality of ultimate product. In order to remove MIBK from aqueous solutions, the means of flat vacuum membrane distillation(VMD) is studied in the paper. The area of the membrane used in the study is 0.02 m 2, the initial volume of feed is 2 L, each experiment was conducted over a time period of 60 120 min. The influences of the factors such as temperature(34.8 55.0 ℃); pressure in the permeate side(10.67 14.67 kPa) and feed flow rate(27.8 69.4 mL/s) were experimentally studied. Increasing the temperature or reducing the pressure in the permeate side results in a faster removal of MIBK; however there is a decrease in removal factor β , increasing the feed flow rate results in a faster removal of MIBK and an increase of removal factor β , especially in the range of lower flow rate. The study indicates that the aim of MIBK removal and recycle from dilute aqueous solutions can be achieved by VMD.

CeCl_3·7H_2O as an efficient catalyst for one-pot synthesis of β-amino ketones by three-component Mannich reaction

Cerium trichloride heptahydrate(CeCl_3·7H_2O) was found to be an efficient and recyclable catalyst for the three-component direct Mannich reaction of anilines and benzaldehydes with acetophenone.This protocol has advantages of high yield,no environmental pollution,mild condition,and simple work-up procedure.

Synthesis and characterization of quaternized poly(phthalazinone ether sulfone ketone)for anion-exchange membrane

Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.

Silica gel supported AlCl_3 catalyzed Friedel-Crafts acylation of aromatic compounds

Silica gel supported aluminium trichloride（SiO2-AlCl3） has been shown to be a mild,efficient,and chemoseiective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds with acid chlorides.The catalyst can be reused up to five times after simple washing with ether and is stable（as a bench top catalyst）.

UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)

Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly（ether ether ketone） （PEEK） with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide（AAm） with ultraviolet（UV） irradiation in the presence or absence of benzophenone（BP）. The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characteriza tion of modified PEEK using scanning electron microscopy（SEM）, energy-disperse spectrometer（EDS） and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed.

A green method for the synthesis of bis-indolylmethanes and 3,3'-indolyloxindole derivatives using cellulose sulfuric acid under solvent-free conditions

A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3 -diindolyloxindole derivatives from the reaction of indoles with various aldehydes and ketones in the presence of cellulose sulfuric acid under solvent-free conditions is reported.The significant features of this procedure are high yields of the products,mild reaction,solvent-free condition and non-toxicity of the catalyst.

Gallium trichloride-catalyzed conjugate addition of indole and pyrrole to α,β-unsaturated ketones in aqueous media

Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.