Synthesis of 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in aqueous medium at room temperature

The reaction of dimedone with various aromatic aldehydes produces 2,2＇-arylmethylene bis （3-hydroxy-5,5-dimethyl-2- cyclohexene-l-one） in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification.

An Improved Synthesis of Azines under Solvent-Free Conditions

A new convenient and environmentally benign procedure for synthesis of azines from hydrazme sulfate with several aromatic aldehydes coupled with grinding is studied. This reaction is carried out under solvent-free conditions and in absence of catalyst to afford high yields of relevant azines.

Uncatalyzed Condensation Reactions between Aromatic Aldehydes and Thiobarbituric Acid in Water

A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and 1H NMR spectra.

New branched benign compounds including double antibiotic scaffolds:synthesis,simulation and adsorption for anticorrosion effect on mild steel

In this study,two novel environmental benign double antibiotic norfloxacin or ciprofloxacin scaffolds included branched molecules were prepared by multi-step routes and purified by simple performance,which were used as the target compounds(TCs).Meanwhile,a single norfloxacin or ciprofloxacin skeleton based molecules were synthesized as the reference compounds(RCs).The molecular geometry optimization and material simulation computation revealed that TCs presented smaller HOMOLUMO energy gaps and larger binding energy levels on mild steel surface than RCs.The chemical adsorption of TCs on steel surface was confirmed by X-ray photoelectron spectroscopy,which could be processed by TCs chelation with iron ions.It was shown that TCs could be self-adsorbed on steel surface,which was demonstrated by atomic force microscopy and scanning electron microscopy.The anticorrosion of the studied compounds for mild steel in HCl solution was investigated by electrochemistry analysis.The results suggested that the anticorrosion efficiency could reach 95.86%(TC1)and 97.05%(TC2)at 0.050 mmol·L^(−1) based on electrochemical impedance spectroscopy,which were much better than RCs(RC1,69.23%;RC2,74.16%).The adsorption isotherms of TCs on steel were further fitted,and a deep insight on adsorption was discussed.

A green repair pathway for spent spinel cathode material:Coupled mechanochemistry and solid-phase reactions

A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.

PEG-OSO_3H as an efficient and recyclable catalyst for the synthesis of β-amino carbonyl compounds via the Mannich reaction in PEG-H_2O

Sulfuric acid-modified polyethylene glycol 6000（PEG-OSO_3H） was applied as an efficient and recyclable catalyst for the synthesis ofβ-amino carbonyl compounds via the Mannich reaction between aldehydes,aromatic ketones and aromatic amines at room temperature using PEG400-H_2O（1：1） as environment-friendly solvents.The reactions were completed in short times and mild reaction conditions with good to excellent yields.

H_6P_2W_(18)O_(62)á18H_2O: A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient,effcient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot,three-component reaction of 4-hydroxy-6-methylpyran-2-one,aldehydes and malononitrile in water using H6P2W18O62á18H2O as catalyst.Reusability of the catalyst and reaction media,short reaction times and easy isolation of products are some added advantages of the present methodology.

Supported bimetallic catalyst Pt-Pb/SiO2 for selective conversion of nitrobenzene to p-aminophenol in pressurized CO2/H2O system

Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO2/H2O system.Among the bimetallic catalysts prepared,Pt-Pb/SiO2 is the best and nitrobenzene could be converted to paminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at110 ℃ under 5 MPa CO2 and 0.2 MPa H2.

Synthesis of poly(silyl ether)s via copper-catalyzed dehydrocoupling polymerization

The development of efficient method to prepare poly(silyl ether)s(PSEs)is highly desirable.Herein,an environmentally sustainable copper-catalyzed dehydrocoupling polymerization was developed with good yields and high molecular weight(up to 48,400 of Mn and up to 97%yield).Monomers of different types(AB type or AA and BB type)are suitable to afford PSEs.The PSEs show good thermal stability and low glass-transition temperature.