97-41-6Relevant articles and documents
Asymmetric cyclopropanation method of copper-catalyzed olefin and application of asymmetric cyclopropanation method
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Paragraph 0082-0086, (2021/05/22)
The invention discloses an asymmetric cyclopropanation method of copper-catalyzed olefin and application thereof. The copper catalyst adopted by the method is generated in situ from a metal copper precursor and a chiral P, N, N-ligand in a reaction medium. The method has the characteristics of cheap catalyst, simple ligand preparation, high activity, high selectivity, mild reaction conditions, simple operation and the like, can realize continuous operation, and is suitable for large-scale industrial production. The method is also suitable for asymmetric synthesis of chiral first chrysanthemic acid which is an important intermediate of pyrethroid pesticides, the yield can reach 80%, the enantioselectivity can reach 85%, and the method can be applied to industrial preparation.
Cycloaddition Reactions of Alkene Radical Cations using Iron(III)-Phenanthroline Complex
Cho, Yong Hyun,Kim, Jae Hyung,An, Hyeju,Ahn, Kwang-Hyun,Kang, Eun Joo
supporting information, p. 2183 - 2188 (2020/04/29)
Single electron oxidation of electron-rich alkenes using the iron(III)-phenanthroline complex produced electrophilic alkene radical cations, which promoted efficient radical cation [2+1] cycloaddition reactions with diazo compounds. Subsequent chain propagation afforded tri- and tetra-substituted cyclopropanes. This methodology was also expanded to [3+2] cycloaddition reactions with vinyl diazoesters, validating this sustainable, first-row transition metal iron system for the single electron redox reactions. (Figure presented.).
High-yield ethyl chrysanthemate preparation method
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Paragraph 0037-0080, (2020/12/08)
The invention belongs to the technical field of chemical processes, and specifically relates to a high-yield ethyl chrysanthemate preparation method. The high-yield ethyl chrysanthemate preparation method comprises the following steps: (1) diazotization: a step of adding water, glycine ethyl ester acid salt, glacial acetic acid and dimethyl carbonate as solvents into a diazotization kettle, dropwisely adding a sodium nitrite aqueous solution into the diazotization kettle, and carrying out a reaction so as to a diazo liquid; (2) cyclization: a step of putting 2,5-dimethyl-2,4-hexadiene into a cyclization kettle, and carrying out a reaction with cuprous chloride as a catalyst so as to obtain a cyclized solution; (3) desolventizing: a step of sending the cyclized solution into a high-yield desolventizing tower to remove the solvents so as to obtain a crude ethyl chrysanthemate product; and (4) distillation: a step of putting the crude ethyl chrysanthemate product into a distillation kettle, and carrying out vacuum distillation so as to obtain the high-purity ethyl chrysanthemate. The high-yield ethyl chrysanthemate preparation method provided by the invention has the following beneficial effects: when the dimethyl carbonate is used as a solvent, a diazotization reaction can be carried out more completely, so the loss of raw materials is reduced; and meanwhile, the yield of ethyl chrysanthemate in the subsequent cyclization reaction can be improved.