8 results about "Grubbs' catalyst" patented technology

The embodiment of the invention provides an asymmetric brush polymer and a preparation method thereof. The preparation method comprises the following steps: step S1, enabling 5-norbornene-2-exo, 3-exo-dimethanol to react with 2-(dodecyl thiocarbon thio) propionic acid, so as to obtain a norbornene derivative with 2-(dodecyl thiocarbon thio) propyl ester and a hydroxyl unit at the same time; s2, enabling the norbornene derivative to react with caprolactone and methyl acrylate by utilizing a light irradiation reaction system in the presence of a ring-opening polymerization catalyst and a photocatalyst, so as to obtain an asymmetric macromonomer containing polymethyl acrylate and polycaprolactone block units at the same time; s3, enabling the asymmetric macromonomer to react in the presence of a Grubbs catalyst, so as to obtain the asymmetric brush type polymer. By applying the technical scheme provided by the invention, the technical problems that in the prior art, the synthesis steps of the asymmetric brush type polymer are tedious, multiple purification is needed, and the molecular weight and distribution of the polymer are difficult to effectively control can be effectively solved.

The present application relates to the field of biotechnology, and particularly to an enzyme composition and its application in preparing ceramide NP. The present application provides a new method for synergistically catalyzing the synthesis of ceramide NP by multiple enzymes; the method is based on enzyme directed evolution, and uses propenal and glycine as starting substrates, and under the action of mutant glycine aldolase, enaminoketol reductase, pentenoate ligase, olefin reductase, phosphite dehydrogenase and polyphosphate kinase, and in cooperation with a metal catalyst Grubbs Catalyst, to realize the synthesis of high-efficiency and high-purity ceramide NP; compared with the traditional microbial fermentation method, the synthesis path of the present application has the advantages of mild reaction condition, convenience for continuous production, short conversion period (<8h), low cost and high product purity (byproduct content <0.5%), and is suitable for the demand of industrial large-scale production.

The present invention relates to a method for synthesizing a phosphoniamidate derivative in a single step or directly through ultrasonic irradiation and portionwise addition of the Hovayda-Grubbs catalyst.

The invention discloses a atractylenolide synthesis intermediate and a synthesis method of atractylenolide and a derivative thereof, and the method comprises the following steps: oxidizing methyl in a compound 17 to prepare a compound 18; preparing a compound 19 from the compound 18 under the action of a Grubbs catalyst; carrying out hydrogenation reduction on the compound 19 to prepare a compound 20; dehydrating and eliminating the compound 20 to obtain a compound 21; hydrolyzing the compound 21 to obtain a compound 22; according to the invention, asymmetric total synthesis of atractylone, 13 kinds of eudecane atractylenolides and lactam natural products is finally realized, the technical bottleneck of chiral control of the compounds is broken through for the first time, the convergent design has both step economy and derivative universality, and especially, the type of a nucleophilic reagent is changed by a system, so that the method is suitable for industrial production. And derivative libraries with various structures are successfully constructed.

This invention discloses a modified bamboo-based fiber composite material and its preparation method. Specifically, it relates to a modified bamboo-based fiber composite material, characterized by comprising the following components in parts by weight: 80-100 parts modified bamboo fiber, 70-90 parts epoxy resin, and 2-5 parts curing agent. The modified bamboo fiber is prepared through the following steps: Step 1: Immersing the bamboo fiber in a 10-15% sodium hydroxide solution at 70°C for 3-6 hours, then washing with water until neutral and drying; Step 2: Immersing the bamboo fiber treated in Step 1 in an aqueous mixture containing 0.6%-1.4% Grubbs catalyst, stirring and soaking for 12-24 hours; Step 3: Mixing the dried bamboo fiber treated in Step 2 with dicyclopentadiene microcapsule powder at a mass ratio of 30-50:1 until homogeneous. The modified bamboo-based fiber composite material prepared by this invention exhibits good mechanical properties.

[Problem] To easily produce an oxypropylene group-containing glycol ether that substantially contains no allyl group-containing impurity and does not adversely affect a polymerization reaction of a polyether-polysiloxane block copolymer when used as a reaction solvent or a diluent, by easily separating the oxypropylene group-containing glycol ether by distillation or the like in a facility and a reaction process that are industrially relatively easy and simple. [Solution] An oxypropylene group-containing glycol ether production method which includes a step for isomerizing an allyl group-containing impurity contained in an oxypropylene group-containing glycol ether by using a ruthenium carbene complex that is known as a Grubbs catalyst, and preferably further includes a purification step for separating the oxypropylene group-containing glycol ether by using a means such as distillation.

A prepolymer and a resin composition containing the prepolymer are provided. The prepolymer is obtained from a prepolymerization reaction of a mixture, the mixture including 100 parts by weight of a compound of Formula (1) and 0.01 to 0.09 part by weight of a Grubbs catalyst. The resin composition may be used to make various articles, including a prepreg, a resin film, a laminate or a printed circuit board, and at least one of the following properties can be improved, including copper foil peeling strength and passive intermodulation.

The invention provides a binuclear ruthenium carbene catalyst and a preparation method and application thereof.The binuclear ruthenium carbene catalyst has the structure shown in the formula I. The binuclear ruthenium carbene complex has the advantages of being easy to synthesize, high in activity, small in catalyst dosage and high in stability, and can solve the problem that in cycloolefin metathesis polymerization reaction, an existing Grubbs catalyst is not prone to generating side reactions in the prior art. The problems of large catalyst dosage, low catalyst stability and the like exist.