Efficient Conversion Of Epoxides Research Articles

Monodentate H-bond donor bifunctional catalyst in fixation of atmospheric pressure carbon dioxide into cyclic carbonates

The efficient conversion of epoxides and CO2 into cyclic carbonates by employing H-bond donor (HBD) and nucleophilic halide cooperating catalysis under mild conditions is an attractive research topic. Herein, we report a new onium halide bearing a CON(H) moiety as a weak HBD catalyst to facilitate the cycloaddition reaction of epoxides and CO2 under mild conditions. The structural influences on the catalytic activity were scrutinized, which included tunable substituents, the distance between functional groups, and counter anions. The result indicated that the catalyst of the bis-meta-substitutions on an aromatic ring exhibited excellent activity for converting epichlorohydrin into cyclic carbonate under atmospheric pressure at 25–70 °C. Twelve terminal epoxides were converted into corresponding cyclic carbonates in 72–99 % isolated yield. A reasonable activation mechanism was proposed and validated by using control experiments and NMR titrations. In addition, the good recyclability proves that the onium halide is a sustainable green organocatalyst.

A Porous CoII-MOF for CO2 Cycloaddition and the Protective Effect against Staphylococcus aureus Systemic Infection in the Department of Ultrasound

A new metal-organic framework (MOF) based on CoII ions as nodes, [Co2(H2O)3(cada)](DMF)4, which has coordinated water molecules at the occupied CoII sites along with a suitable pore environment, was constructed by reaction of 5,5′-(9H-carbazole-2,7-diyl)diisophthalic acid (H4cada) and Co(NO3)2·6H2O in a water and DMF mixed solvent. The resulting activated MOF 1ais able to uptake considerable amounts of CO2 at room temperature, and be further used for the efficient conversion of epoxides along with CO2 into cyclic carbonates under mild conditions without a co-catalyst. To control intra-hospital cross-infection in the Department of Ultrasound, the anti-bacterial activity of the compound was assessed in a systemic Staphylococcus aureus infection mouse model. The survival rate of systemic Staphylococcus aureus infected mice after compound treatment was determined to evaluate protective effect of the compound invivo. The number of colony-forming units (CFUs) in the organs of infected mice was also counted for further verification.

Efficient Conversion of Epoxides into Carbonates with CO2 and a Single Organocatalyst: Laboratory and Kilogram-Scale Experiments

Cheap and readily available 2-aminopyridine and related compounds can be used as organocatalysts for the conversion of epoxides into cyclic carbonates. This reaction gives high conversions under solvent-free conditions and is amenable to a kilogram-scale conversion under mild conditions.

A green protocol for rapid and efficient conversion of epoxides to thiiranes using alumina immobilized thiourea at solvent-free conditions

GRAPHICAL ABSTRACT

ChemInform Abstract: Efficient Conversion of Epoxides into β‐Hydroperoxy Alcohols Catalyzed by Antimony Trichloride/SiO2.

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Efficient Conversion of Epoxides into β-Hydroperoxy Alcohols Catalyzed by Antimony Trichloride/SiO2

Efficient ring-opening of various epoxides with hydrogen peroxide, catalyzed by antimony trichloride/SiO2, afforded the corresponding β-hydroperoxy alcohols in good to excellent yields under mild reaction conditions. The reactions were efficiently promoted by ultrasound irradiation.

Catalytic Conversion of Epoxides to 1,3-Dioxolanes with Phosphomolybdic Acid (PMA) in Solution and under Solvent-Free Conditions

The fast and efficient conversion of epoxides into 2,2-dimethyl-1,3-dioxolanes was studied with catalytic amounts of phosphomolybdic acid (PMA) (0.1-0.2 mol %) at room temperature in solution and under solvent-free conditions. The products were obtained in high to excellent yields within 1–2 min.

Efficient and Catalytic Conversion of Epoxides into 1,3‐Dioxolanes with LiBF4

Lithium tetrafluoroborate catalysis the efficient conversion of epoxides with acetone to the corresponding 1,3‐dioxolanes in excellent isolated yields.

Highly Regioselective Conversion of Epoxides to β-Hydroxy Nitriles with Cyanide Exchange Resin

A simple and regioselective method is described for the efficient conversion of epoxides to β-hydroxy nitriles using Amberlite IRA-400 supported cyanide. The reactions occur in the absence of catalyst and furnish the corresponding β-hydroxy nitriles in high yields.

Efficient Conversion of Epoxides to Thiiranes with Thiourea Catalyzed by Tin(IV) Porphyrin

Conversion of various epoxides to the corresponding thiiranes is achieved by thiourea in the presence of tin(IV) meso-tetraphenylporphyrin with excellent yields under non-aqueous conditions.