65166-97-4Relevant academic research and scientific papers
Ethylene in organic synthesis: A new route to anticholenergic pyrrolidinoindolines, and other molecules with all carbon-quaternary centers via asymmetric hydrovinylation
Lim, Hwan Jung,Rajan Babu
, p. 6596 - 6599 (2011)
The asymmetric hydrovinylation (1 mol % Ni-cat., 1 atm, ethylene, >98% ee) products from 1-methylenetetralines are readily converted into 3, 3-disubstituted oxindoles and subsequently to pyrrolidinoindolines. These hydrovinylation products are also useful for the syntheses of enantiopure benzomorphans.
SYNTHESIS OF (-)- AND (+)-ESERMETHOLE VIA CHEMICAL RESOLUTION OF 1,3-DIMETHYL-3-(2-AMINOETHYL)-5-METHOXYOXINDOLE
Pallavicini, Marco,Valoti, Ermanno,Villa, Luigi,Lianza, Francesca
, p. 111 - 116 (1994)
A new synthesis of (-)- and (+)-esermethole (2 and 7 respectively), penultimate intermediates to (-)- and (+)-physostigmine, is described.Phase-transfer catalyzed dimethylation of 3-cyanomethyl-5-methoxyoxindole (3) and successive hydrogenation of the cyano group gave 1,3-dimethyl-3-(2-aminoethyl)-5-methoxyoxindole (5), which was efficiently resolved with optically active tartaric acids.Subsequent conversion to a carbamate and reductive cyclization performed by a standard method afforded both the enentiomers of esermethole.The enantiomeric excesses, determined by chiral HPLC analysis, were greater than 99.5percent.In particular, analitycal HPLC resolution of 5, previously reported as unfeasible, was achieved.
Nickel-Catalyzed Enantioselective Carbamoyl Iodination: A Surrogate for Carbamoyl Iodides
Abel-Snape, Xavier,Glorius, Frank,Lautens, Mark,Marchese, Austin D.,Mirabi, Bijan,Whyte, Andrew,Wollenburg, Marco
, p. 4780 - 4785 (2020/05/19)
This work reports the enantioselective formal transfer of a carbamoyl iodide across a 1,1-disubstituted styrene using Ni-catalysis. Employing an air-stable Ni(II) precatalyst and a commercially available chiral ligand ((S)-tBuPHOX), enantioenriched 3,3-disubstituted iodooxindoles were obtained in up to 90% yield and up to 97:3 e.r. This methodology was applied to the total synthesis of (-)-esermethole and (-)-phenserine.
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 (2019/05/24)
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.
The photocatalysis synthetic alkaloid (by machine translation)
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Paragraph 0126; 0127; 0128, (2018/11/22)
The present invention provides a catalytic synthesis method of living beings, the alkaloid comprises indole fused ring class and indole spiro compound, the process is as follows: in order to nitrogen aryl acrylamide as raw materials in under the photocatalysis with peroxide synthesis 3 - acetal 2 - indole compound, obtained through hydrolysis 3 - formyl - 2 - indole compound, further reducing synthetic alkaloid, the method routes mild, efficiency is high-efficient. The reaction in the illumination can occur under the room temperature, mild condition, has better substrate versatility and functional group tolerant. (by machine translation)
Generation of All-Carbon Quaternary Stereocenters at the C-3 Carbon of Lactams via [3,3]-Sigmatropic Rearrangement and Revision of Absolute Configuration: Total Synthesis of (-)-Physostigmine
Pandey, Ganesh,Khamrai, Jagadish,Mishra, Akash
supporting information, p. 166 - 169 (2018/01/17)
A diastereoselective (up to >99%) route to all carbon quaternary stereocenters at the C-3 position of cyclic lactams has been developed via Johnson-Claisen rearrangement of ?-hydroxy-α,β-unsaturated lactams. It has been observed that olefin geometry plays an important role in the development of the absolute stereochemistry of the product. Dependence of product configuration on the olefin geometry is explained by postulating probable transition states. The success of this method has been shown for multigram-scale synthesis of these substituted lactams from commercially available cheap starting materials. The synthetic usefulness of this method is also demonstrated by carrying out the total synthesis of (a-)-physostigmine.
Pd(0)-Catalyzed Chemoselective Deacylative Alkylations (DaA) of N-Acyl 2-Oxindoles: Total Syntheses of Pyrrolidino[2,3- b]indoline Alkaloids, (±)-Deoxyeseroline, and (±)-Esermethole
Kumar, Nivesh,Gavit, Vipin R.,Maity, Arindam,Bisai, Alakesh
, p. 10709 - 10735 (2018/09/29)
We report an efficient Pd(0)-catalyzed deacylative allylation of N-acyl 3-substituted 2-oxindoles via the coupling of in situ generated nucleophiles (3 and 4) with allyl electrophiles for the synthesis of a variety of 2-oxindoles with C3-quaternary centers. Gratifyingly, this alkylation process is found to be highly chemoselective in nature, where a C-C bond formation is completely predominant over a C-N bond formation. A variety of key intermediates were synthesized utilizing an aforementioned methodology.
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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Paragraph 0013; 0048-0051, (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.
FeCl3-Catalyzed Allylation Reactions onto 3-Hydroxy-2-oxindoles: Formal Total Syntheses of Bis-cyclotryptamine Alkaloids, (±)-Chimonanthine, and (±)-Folicanthine
Kinthada, Lakshmana K.,Medisetty, Sai Raghavendra,Parida, Amarchand,Babu, K. Naresh,Bisai, Alakesh
, p. 8548 - 8567 (2017/08/23)
An FeCl3-catalyzed efficient strategy for the allylation reactions of 3-hydroxy-2-oxindoles with allyltrimethylsilane has been developed. The reaction affords a variety of 2-oxindoles having quaternary center at the pseudobenzylic position in an operationally simple and inexpensive procedure. Control experiments using enantioenriched 3-hydroxy-2-oxindole show that the reaction proceeds through in situ generated 2H-indol-2-one (8). The methodology presents an efficient and concise access to the pyrroloindoline alkaloids (±)-deoxyeseroline (1a), (±)-esermethole (1b), (±)-physostigmine (1c), (±)-phenserine (1d), and (±)-physovenine (1e). Eventually, we extrapolated the scope of this methodology to the formal total syntheses of dimeric cyclotyrptamine alkaloids (±)-chimonanthine (3a), (±)-folicanthine (3c), and (±)-calycanthine (4).
