104069-12-7Relevant articles and documents
Photocatalytic Cascade Radical Cyclization Approach to Bioactive Indoline-Alkaloids over Donor-Acceptor Type Conjugated Microporous Polymer
Ou, Wei,Zhang, Guoqiang,Wu, Jie,Su, Chenliang
, p. 5178 - 5183 (2019)
Herein, we describe a visible-light-induced radical strategy for the 1,2-formylarylation of N-arylacrylamides via the C-H activation of 1,3-dioxolane using a carbazolic-cyano conjugated microporous polymer (CC-CMP) as a metal-free photocatalyst. This process provides an efficient and mild approach for constructing highly functionalized formyl-substituted oxindoles, which are valuable building blocks that allow rapid access to various important heterocycle-fused and spirocyclic indole alkaloids. Utilizing this strategy, bioactive alkaloids, such as (±)-desoxyeseroline, (±)-esermethole, and (±)-N-Me-coerulescine, have been concisely synthesized in up to 74% overall yield from low-cost acrylamides and 1,3-dioxolane. The overall yields of our approach are much higher than those of conventional multistep methods. Gram-scale syntheses of natural alkaloids have been demonstrated, highlighting the practical utility of this protocol. The use of CC-CMP photocatalysts, which are metal-free, flexible, stable, effective, and reusable, making this strategy appealing to advanced chemical manufacturing.
An efficient synthesis of optically active physostigmine from tryptophan via alkylative cyclization
Kawahara, Michiaki,Nishida, Atsushi,Nakagawa, Masako
, p. 675 - 678 (2000)
(Equation Presented) Physostigmine A new and efficient synthetic route to physostigmine is described. Corey-Kim reagent reacted with tryptamine or tryptophan carbamates to give 3a-(methylthiomethyl)hexahydropyrrolo[2,3-b]indole skeletons. Formal total synthesis of racemic and chiral physostigmine was accomplished in excellent overall yields, in short steps.
Metal-Free Synthesis of Oxazolidine-2,4-diones and 3,3-Disubstituted Oxindoles via ICl-Induced Cyclization
Yi, Wei,Fang, Xing-Xiao,Liu, Qing-Yun,Liu, Gong-Qing
, p. 6671 - 6681 (2019/01/04)
A metal-free method for the construction of oxazolidine-2,4-diones and oxindoles was discussed. Using iodine monochloride (ICl) as both the reaction promoter and iodide source, the iodolactonization of N-Boc acrylamides proceeded readily and provided the corresponding iodo oxazolidine-2,4-diones and oxazolidin-2-ones in good isolated yields. The obtained oxazolidine-2,4-diones can be used as key intermediates in the synthesis of toloxatone. When N-alkyl-N-arylacrylamide derivatives were subjected to the same reaction, iodocarbocyclization products 3,3-disubstituted oxindoles were obtained. The obtained oxindoles can be used as key intermediates in the synthesis of the alkaloids (±)-esermethole and (±)-physostigmine.
Preparation method for physostigmine precursor compound
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, (2017/09/13)
The invention relates to physostigmine and provides a preparation method for a physostigmine precursor compound. The physostigmine precursor compound is prepared with 5-methoxytryptamine as a starting raw material through amino protection, intramolecular cyclization, methylation and amide reduction. The preparation method has the advantages of simple synthesis route, usage of cheap and easily available synthesis reagents, simple synthesis operation, friendliness to environment and the like and is highly feasible in industrial production. In particular, a cyclization reagent, i.e., 1,3-dichloro-5,5-dimethylhydantoin, used in the key intramolecular cyclization is a commercial germicide and disinfectant and is cheap, easily available and friendly to environment. The physostigmine precursor compound used as a synthesis precursor or intermediate for physostigmine is also applicable as a synthesis precursor for phenserine and a variety of physostigmine derivatives and thus has good application value and development potential.
