A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.

Oxidation of benzyl alcohols to ketones and aldehydes by O3 process enhanced using high-gravity technology

In this study,a practical process for ozonization of benzyl alcohols to ketones and aldehydes in a rotating packed bed(RPB-O3)reactor has been developed.Using 1-phenylethanol as a model reactant,the performance of RPB-O3 process in different solvents has been compared with the commonly used stirred tank reactor(STR-O3).Ethyl acetate was the optimum solvent for the conversion of 1-phenylenthanol to acetophenone in RPB-O3 process,with 78%yield after 30 min.In a parallel STR-O3 experiment,the yield of acetophenone was50%.Other experimental variables,i.e.O3 concentration,reaction time,high-gravity factor and liquid flow rate were also optimized.The highest yield of acetophenone was obtained using O3 concentration of 80 mg·L-1,reaction time of 30 min,high gravity factor of 40 and liquid flow rate of 120 L·h-1.Under the optimized reaction conditions,a series of structurally diverse primary and secondary alcohols was oxidized with(19%–92%)yield.The ozonization mechanism was studied by Electron Paramagnetic Resonance(EPR)spectroscopy,monitoring the radical species formed upon self-decomposition of O3.The characteristic quadruple peak with the 1:2:2:1 intensity ratio that corresponds to hydroxyl radicals(·OH)was observed in the electron paramagnetic resonance(EPR)spectrum,indicating an indirect oxidation mechanism of alcohols via·OH radical.

Silicotungstic Acid Modified Bentonite: An Efficient Catalyst for Synthesis of Acetal Derivatives of Aldehydes and Ketones

Acetals and ketals are among the important materials of organic synthesis and as protecting agent of carbonyl functionality. A milder, efficient and green synthesis of acetals and ketals has been developed using Silicotungstic acid modified Bentonite (STA-Ben) as a catalyst. STA-Ben has been synthesized and characterized by various analytical techniques. It has been found to be an efficient and reusable catalyst for the synthesis of acetyl derivatives in excellent yields. In order to elucidate the efficiency of the STA-Ben as catalyst, reaction has also been performed using various catalysts. The reaction conditions (time and amount of catalyst) have been optimized using various catalysts. The products of the various reactions have been characterized by FT-IR, NMR.

Efficient Synthesis of Dicycloalkenopyridines:One-pot Multicomponent Condensation of Aldehydes with Cyclic Ketones

Under microwave irradiation, the one-pot multicomponent condensation reaction of three moles of aromatic aldehydes with two moles of cyclic ketones having free a,a＇-methylene positions such as cyclopentanone or cyclohexanone in the presence of ammonium acetate and acetic acid afforded dicycloalkenopyridines with two a-arylidene groups in high yields. Under the similar reaction condition, the reaction of aromatic aldehydes with 1-tetralone having only one a-methylene position alternatively resulted in 10-aryl-2,3：5,6-dibenzoacridines.

Reduction of Aromatic Aldehydes and Ketones with Acyloxy Substituent at the Ortho-position by NaBH_4 in the Presence of Waters

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Metal-free catalytic reduction of aldehydes,ketones,aldimines,and ketimines

The metal-free combination of catalytic amounts of PPh3,B（C6F5）3,and PhSiH_3 can efficiently hydrosilylate aldehydes, ketones,aldimines and ketimines to afford the corresponding reduction products in good yields.

Mechanochemical Reaction of Aromatic Ketones and Aldehydes in the Presence of Zn-ZnCl_2

The solvent-free reactions of aromatic ketones and aldehydes in the presence of Zn-ZnCl2 were performed with the aid of high-speed vibration mill, Retsch MM200 mixer mill and Retsch RM100 mortar grinder to give pinacol coupling and reduction products in varying yields.

The Reaction of ∝, β-epoxyketones with methoxymethylenetriphenylphosphorane, A New Approach to ∝-alkylsubstituted-γ-hydroxy-d, β-unsaturated aldehydes

The reaction of α, β-epoxyketones with methoxymethylenetriphenyl- phosphorane provides a method for the preparation of α-alkylsubstituted γ-hydroxy-α, β-unsaturated aldehydes with one carbon homologation and retention of configuration.

A perspective on recent findings and future strategies for reactive aldehyde removal in spinal cord injury

Acrolein in spinal cord injury:The propensity of reactive aldehydes such as acrolein to both initiate and perpetuate tissue damage after spinal cord injury (SCI) is well established.Formed primarily from lipid peroxidation,acrolein is known to be one of the most reactive aldehydes.Acrolein will quickly overwhelm endogenous clearance mechanisms and antioxidants,and form adductswith lipids,proteins,and DNA.

Efficient electrooxidation of biomass-derived aldehydes over ultrathin Ni V-layered double hydroxides films

Selective upgrading of C=O bonds to afford carboxylic acid is significant for the petrochemical industry and biomass utilization.Here we declared the efficient electrooxidation of biomass-derived aldehydes family over NiV-layered double hydroxides(LDHs) thin films.Mechanistic studies confirmed the hydroxyl active intermediate(-OH*) generated on the surface of NiV-LDHs films by employing electrochemical impedance spectroscopy and the electron paramagnetic resonance spectroscopy.By using advanced techniques,e.g.,extended X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy,NiV-LDHs films with 2.6 nm could expose larger specific surface area.Taking benzaldehyde as a model,high current density of 200 mA cm^(-2)at 1.8 V vs.RHE,81.1% conversion,77.6% yield of benzoic acid and 90.8% Faradaic efficiency were reached,which was superior to most of previous studies.Theoretical DFT analysis was well matched with experimental findings and documented that NiV-LDHs had high adsorption capacity for the aldehydes to suppress the side reaction,and the aldehydes were oxidized by the electrophilic hydroxyl radicals formed on NiV-LDHs.Our findings offer a universal strategy for the robust upgrading of diverse biomass-derived platform chemicals.

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.

Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO:Process optimization and reaction kinetics

As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.

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. .

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...

Environment friendly protocol for the synthesis of nitriles from aldehydes

A rapid and eco-friendly one-pot protocol for the synthesis of nitriles has been developed by treating various araldehydes bearing electron withdrawing as well as electron donating groups with hydroxylamine hydrochloride in the presence of non-toxic,non-corrosive and reusable zinc oxide（ZnO） as the catalyst under solvent-free microwave irradiation.The present approach offers the advantages of a clean reaction,simple methodology,employing readily available catalyst,short reaction duration（〈1 min）,high selectivity;and high yield（90-98%）.

A Facile Synthesis of β-Cyclodextrin Monoaldehyde

β -Cyclodextrin (β -CD) was directly oxidized in high yield to the corresponding monoaldehyde by cyclized 2-iodoxybenzoic acid (IBX) in DMSO.

Ferrous methanesulfonate as an efficient and recyclable catalyst for chemoselective synthesis of 1,1-diacetate from aldehydes

Ferrous methanesulfonate catalysing the conversion of aromatic, heteroaromatic, unsaturated, and aliphatic aldehydes to 1,1- diacetates at room temperature under solvent-free condition has been developed. The catalytic activity of seventeen metal methanesulfonates was compared under the same condition, ferrous methanesufonate proved to be the best. It can be easily recovered and reused for several times without distinct deterioration in catalytic activity. During the competitive protection between a ketone and an aldehyde group with Ac20, 1,1-diacetate formed exclusively with the aldehyde group. 2009 Min Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.