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 0018-0023, (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 and Synthetic Application of Chloro- And Bromofuroxans
Ando, Akihiro,Hasebe, Hayu,Hayashi, Masahiko,Kim, Hojin,Matsubara, Ryosuke,Tsuneda, Takao
, p. 5959 - 5972 (2020/05/26)
Furoxans are potentially useful heteroaromatic units in pharmaceuticals and agrichemicals. However, the applications for furoxan-based compounds have been hampered due to the underdevelopment of their synthetic methods. Herein, we report a new synthetic approach for the synthesis of chloro- and bromofuroxans. The starting materials were dichloro- and dibromofuroxans, and the substituents were directly introduced to the furoxan ring in a modular fashion. The synthesized monohalofuroxans served as substrates for the installation of a second substituent to prepare further functionalized furoxans.
