74213-24-4Relevant articles and documents
Asymmetric Total Syntheses of Kopsia Indole Alkaloids
Leng, Lingying,Zhou, Xiaohan,Liao, Qi,Wang, Falu,Song, Hao,Zhang, Dan,Liu, Xiao-Yu,Qin, Yong
, p. 3703 - 3707 (2017)
The asymmetric total syntheses of a group of structurally complex Kopsia alkaloids, (?)-kopsine, (?)-isokopsine, (+)-methyl chanofruticosinate, (?)-fruticosine, and (?)-kopsanone, has been achieved. The key strategies for the construction of the molecular complexity in the targets included an asymmetric Tsuji–Trost rearrangement to set the first quaternary carbon center at C20, an intramolecular cyclopropanation by diazo decomposition to install the second and third quaternary carbon centers at C2 and C7, respectively, and a SmI2-promoted acyloin condensation to assemble the isokopsine core. A radical decarboxylation of an isokopsine-type intermediate results in a thermodynamic partial rearrangement to give N-decarbomethoxyisokopsine and N-decarbomethoxykopsine, two key intermediates for the syntheses of Kopsia alkaloids with different subtype core structures.
Total Synthesis of Actinophyllic Acid
Yoshii, Yu,Tokuyama, Hidetoshi,Chen, David Y.-K.
, p. 12277 - 12281 (2017)
Herein we report a total synthesis of the indolohydroazocine natural product actinophyllic acid. The target molecule was retrosynthetically deconvoluted to render a greatly simplified and symmetrical [4.4.1] bicyclic trienone, the desymmetrization of which was carefully examined under a variety of conditions, including oxidative, reductive, and transition-metal-catalyzed transformations. Ultimately, the successful synthetic strategy featured chemoselective catalytic dihydroxylation, desymmetrizing nitrile oxide dipolar cycloaddition, and palladium-catalyzed aminoarylation to sequentially modify the three olefins within the trienone, followed by a late-stage reductive cascade indolization and alkylation to complete the target molecule.
Synthetic method 3 - bromo -5, 5 - dimethyl -4 and 5 -dihydroisoxazole
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Paragraph 0005; 0024, (2021/12/08)
The invention discloses a synthetic method of 3 - bromo -5, 5 - dimethyl -4 and 5 -dihydroisoxazole, which comprises the continuous synthesis of intermediate dibromoformaldehyde oxime and the synthesis of the product 3 - bromo -5, 5 - dimethyl -4 and 5 -dihydroisoxazole. To the method, the production route is improved firstly through dehydration condensation of glyoxylic acid and hydroxylamine hydrochloride, the obtained intermediate does not need to be discharged, and a bromination reagent is directly added. 1,3 - Dipole ring addition reaction produces the target product, can realize whole production route in-process target product overall yield's improvement, reduces by-product and the generation of three wastes, can also realize the recovery of solvent, and easy and simple to handle, and whole process used raw materials and solvent price are low, are favorable to the control cost, especially be fit for industrial production.
PROCESS FOR PREPARATION OF BROMO FORMIMINE COMPOUNDS
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Page/Page column 16-17, (2020/12/11)
The present invention discloses an improved process for the preparation of bromo-formimine compounds. More particularly, the present invention discloses an improved process for the preparation of bromo-formimine compounds, wherein bromine anion is recycled by using a suitable oxidizing agent.
Synthesis method and application of pyroxasulfone
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Paragraph 0030; 0091; 0097-0197, (2020/09/09)
The invention relates to the technical field of pesticides, and provides a synthesis method of pyroxasulfone, which comprises the steps of: (1) carrying out a hydroxyalkylation reaction, a fluoromethylation reaction and a chlorination reaction on a reaction body (I) to obtain an intermediate 2; and (2) mixing an intermediate 1 and the intermediate 2, adding water to separate out an organic phase to obtain a transition intermediate, and adding a solvent and an oxidizing agent for reaction to obtain pyroxasulfone. The invention further provides application of pyroxasulfone to pesticides. The pyroxasulfone is prepared by the synthesis method. According to the invention, the overall yield of the target product can be increased, the generation of by-products can be reduced, the generation of three wastes is perfectly reduced, and the recycling of the solvent is realized.
