- Preparation method of N-substituted-tetrahydropyridine-3/4-boric acid/ester
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The invention discloses a preparation method of N-substituted tetrahydropyridine-3/4-boric acid/ester, and belongs to the technical field of organic boric acid chemistry. The method comprises the following steps: carrying out a reaction on pyridine-3/4-boric acid/ester and a halide to form a quaternary salt, and reducing the quaternary salt with sodium/potassium borohydride in an aprotic solvent to generate N-substituted-tetrahydropyridine-3/4-boric acid/ester. According to the method, easily-synthesized pyridine-3/4-boric acid/ester is used as a raw material, the product can be obtained through two continuous steps, and the reaction selectivity is high, so that the defect that palladium-catalyzed coupling or ultralow temperature is needed when substituted piperidone is adopted as a raw material is overcome, the method is verified on the hectogram scale, and a concise and efficient synthesis path is provided for preparation of the compound.
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Paragraph 0023-0025
(2020/04/22)
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- New synthesis method of N-substituted-1,2,5,6-tetrahydropyridine-4-boronic acid pinacol ester
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The invention discloses a new synthesis method of N-substituted-1,2,5,6-tetrahydropyridine-4-boronic acid pinacol ester. The new synthesis method of the N-substituted-1,2,5,6-tetrahydropyridine-4-boronic acid pinacol ester comprises the following three reaction steps: firstly, performing reaction on 4-bromopyridine hydrochloride and clR1 to prepare 4-bromine-N-substituted-pyridine chloride; then preparing N-substituted-piperidine-4-alkenyl bromide through NaBH4 reduction; finally, preparing the target product N-substituted-1,2,5,6-tetrahydropyridine-4-boronic acid pinacol ester through a Grignard method and methoxy boric acid ester. The synthesis route has the advantages of high universality, cheap and easily available raw materials, mild reaction condition, few byproducts, high yield andthe like, and the product has high economic property and strong market competitiveness and is suitable for industrialized production. The formula is as shown in the description, wherein R1=-Boc;-Cbz;-Bz;-Bn;-Fmoc;-Me;-Et;-iPr;-Ph.
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Paragraph 0025; 0027-0028
(2019/12/25)
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- Technological method for synthesizing N-substituted-1,2,5,6-tetrahydropyridine-4-boric acid ester
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The invention relates to an organic compound synthesis method, in particular to a technological method for synthesizing N-substituted-1,2,5,6-tetrahydropyridine-4-boric acid ester. The method comprises the step that N-substituted-1,2,5,6-tetrahydropyridine-4-halide serves as a raw material to react with bi-boric acid ester, cuprous halide or cuprous oxide, a ligand and organic base in a solvent, so that N-substituted-1,2,5,6-tetrahydropyridine-4-boric acid ester is obtained. The method is innovative, and easy and convenient to operate, the technological route is short, the cost is low, the product purity is high, the reaction conditions are mild, the situation that metal palladium coupling or a high-activity Grignard reagent and a low temperature condition are adopted in a traditional method is avoided, and the method has potential cost advantage, and is suitable for industrialized scale-up production.
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Paragraph 0020
(2019/06/07)
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- Palladium(0)-catalyzed alkynyl and allenyl iminium ion cyclizations leading to 1,4-disubstituted 1,2,3,6-tetrahydropyridines
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(Chemical Equation Presented) The biologically important title heterocyclic compounds can be synthesized by two methods based on the cyclization of alkynyl and allenyl iminium ions generated in situ in the presence of organometallic reagents (see scheme).
- Tsukamoto, Hirokazu,Kondo, Yoshinori
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p. 4851 - 4854
(2009/02/08)
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