3 results about "Carbonium ion" patented technology

The application discloses a green catalytic hydrogenation preparation method of low-trans fatty acid edible hydrogenated oil, and comprises the following steps: dispersing an amorphous Ni-Fe-P alloy catalyst in pretreated vegetable oil to obtain a catalyst-oil mixture; introducing the catalyst-oil mixture and a hydrogen donor solution into a microchannel reactor with multiple temperature zones to perform gradient hydrogenation reaction; wherein the microchannel reactor is integrated with an electrochemical hydrogen generation unit, and a direct current electric field is applied to at least one temperature zone; after the reaction is completed, the catalyst is separated and recovered, and the hydrogenated oil is post-treated to obtain the low-trans fatty acid edible hydrogenated oil; for the first time, the electrochemical hydrogenation and catalytic transfer hydrogenation two green hydrogenation technologies are integrated in the microchannel reactor, and the reaction path is regulated by combining the electric field, so that the formation of carbonium ion intermediates and double bond isomerization is fundamentally inhibited, the content of trans fatty acids in the final hydrogenated oil is reduced, and the health value of the product is significantly improved.

The invention relates to a preparation method of a W-ZSM-5 molecular sieve, which comprises the following steps: (1) mixing a tungsten source, a silicon source and a long carbon chain quaternary ammonium salt in water to obtain a first mixture, (2) carrying out crystallization treatment on the first mixture, and washing, drying and roasting the crystallized product to obtain the W-ZSM-5 molecular sieve, wherein the long-carbon-chain quaternary ammonium salt is alkyl trimethyl ammonium halide, and alkyl is straight-chain alkyl with more than 12 carbons. When the catalyst is used for olefin catalytic cracking reaction, compared with the traditional silicon-aluminum ZSM-5, the ordered mesopores of the catalyst obviously shorten the diffusion path and inhibit secondary reaction and coking; the carbon positive ion activity is accurately controlled by the moderate and strong acid strength provided by the framework tetra-coordination W and a proper acid center, and acid-diffusion synergy is realized. The catalyst can improve the diene selectivity without sacrificing the conversion rate, and has excellent catalytic stability.

The application provides a preparation method of beta configuration deoxynucleoside, and belongs to the technical field of nucleoside synthesis. The application regulates the stereoselectivity of the reaction by limiting the combination of the type of organic solvent and the base catalyst: in the organic solvent environment, compound A mainly exists in the thermodynamically stable alpha configuration, the low dielectric constant of the solvent effectively inhibits the formation of carbonium ion and the competition of the SN1 path; the solvent has specific strong coordination with the alkali metal cation, successfully strips the anion in compound B, forms a very high nucleophilic activity 'naked anion', and assists positioning through the ion pair effect of the metal cation in the base catalyst; under the kinetic control, the nucleophilic nucleophilic salt species specifically attacks the leaving group of compound A through SN2 back attack, causes the Walden inversion of the chiral center, is converted into the beta configuration, and finally high-yield and high-stereoselective beta configuration deoxynucleoside is obtained.