70354-71-1Relevant articles and documents
Synthesis of (+)-phenserine using an interrupted Fischer indolization reaction
Schammel, Alex W.,Chiou, Grace,Garg, Neil K.
, p. 725 - 728 (2012)
A concise synthesis of the Alzheimer's therapeutic (+)-phenserine is described. The approach features an interrupted Fischer indolization to construct the pyrrolidinoindoline core, in addition to a classical resolution to arrive at phenserine in enantioenriched form.
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.
Palladium-catalyzed enantioselective domino heck-cyanation sequence: Development and application to the total synthesis of esermethole and physostigmine
Pinto, Artur,Jia, Yanxing,Neuville, Luc,Zhu, Jieping
, p. 961 - 967 (2007/10/03)
An efficient synthesis of functionalized 3-alkyl-3-cyanomethyl-2-oxindole 1 by a palladium-catalyzed domino Heck-cyanation reaction has been developed. Reaction of ortho-iodoanilide 5 with potassium ferro(II)cyanide, K 4[Fe(CN)6], dissolved in DMF in the presence of palladium acetate and sodium carbonate afforded oxindole 1 in good to excellent yields. An enantioselective domino Heck-cyanation process has been developed for the first time using (S)-DIFLUORPHOS as a chiral supporting ligand, and an enantioselectivity of up to 79% ee in the enantiomerically enriched oxindole was obtained under optimized conditions. A concise total synthesis of esermethole and physostigmine, powerful inhibitors of acetyl- and butyryl-cholinesterase, is documented.
Catalytic asymmetric synthesis of either enantiomer of the calabar alkaloids physostigmine and physovenine
Matsuura, Takaharu,Overman, Larry E.,Poon, Daniel J.
, p. 6500 - 6503 (2007/10/03)
A potentially versatile asymmetric route to hexahydropyrrolo[2,3-b]indoles having carbon substituents at C-3a (Scheme 1) is demonstrated through enantioselective total syntheses of the Calabar alkaloids (-)physostigmine (2), (-)-physovenine (10), and their enantiomers. The synthesis of enantiopure (-)physostigmine proceeds from commercially available 2-butyn-1-ol (11) and N-methyl-p-anisidine (15) in 15-20% overall yield by way of eight isolated and purified intermediates. The central step is catalytic asymmetric Heck cyclization of (Z)-2-methyl-2-butenanilide 17 to-form oxindole aldehyde (S)-19 in 84% yield and 95% ee.
2-Azonianorbornene-2-spiro-1'-aziridinium triflate - A novel ethylene immonium ion equivalent: Application to a synthesis of physostigmine
Grieco,Carroll
, p. 4401 - 4404 (2007/10/02)
A unique protocol for either the aminoethylation or the N-methyl aminoethylation of carbonyl compounds featuring the preparation and use of a novel spiroaziridinium salt, 2-azonianorbornene-2-spiro-1'-aziridinium triflate 2, is described.
Rapid Syntheses of Some Indole Alkaloids of the Calabar Bean
Horne, Stephen,Taylor, Nicholas,Collins, Scott,Rodrigo, Russell
, p. 3047 - 3052 (2007/10/02)
A rapid, efficient route to 3,3-disubstituted oxindoles from o-iodo anilines has been developed.It involves the cyclisation of the corresponding fumarate amides 4 and 15 with butyllithium at -100 deg C in the presence of an excess of trimethylchlorosilane.An X-ray crystal structure of 4 suggests that the speed and efficiency of this intramolecular Michael addition is dependent on the conformation adopted by 4 which is particularly suitable for the reaction.This method has been applied to the synthesis of the alkaloids physovenine, physostigmine and esermethole in very high overall yields.
PRACTICAL SYNTHESIS OF UNNATURAL (+)-PHYSOSTIGMINE AND CARBAMATE ANALOGUES
Yu, Qian-Sheng,Brossi, Arnold
, p. 745 - 750 (2007/10/02)
Details of a synthesis of unnatural (+)-physostigmine (5) prepared from urea 1 via (+)-eseroline (4) are given.Preparation of (+)-octylcarbamate 6, (+)-benzylcarbamate 7, (+)-phenylcarbamate 8 and (+)-N-methylphysostigmine (9) from (+)-eseroline (4) is also described.
Comparison of (-)-Eseroline with (+)-Eseroline and Dihydroseco Analogues in Antinociceptive Assays: Confirmation of Rubreserine Structure by X-ray Analysis
Schoenenberger, Bernhard,Jacobson, Arthur E.,Brossi, Arnold,Streaty, Richard,Klee, Werner A.,et al.
, p. 2268 - 2273 (2007/10/02)
The enantiomers of eseroline bind to opiate receptors of rat brain membranes with equal affinities and show opiate agonist properties as inhibitors of adenylate cyclase in vitro.However, only (-)-eseroline shows potent narcotic agonist activity in vivo, similar to that of morphine.Neither (-)-noreseroline, (+)-eseroline, nor the open dihydroseco analogue (-)-8 shows analgetic effects in vivo.The structure of rubreserine being a resonance hybrid of an o-quinone with its zwitterionic mesomer is confirmed by solid-state X-ray diffraction analysis.
Synthesis of some quaternary ammonium alkylating agents and their effects on soman-inhibited acetylcholinesterase
Gray,Platz,Chang,Leverone,Ferrick,Kramer
, p. 111 - 116 (2007/10/02)
A number of compounds were synthesized and tested for their ability to realkylate the phosphonate anion of 'aged', soman-inhibited acetylcholinesterase. None were found able to do so, but two of the compounds in particular, [2-(4-pyridyl)ethyl]diethylmethylammonium iodide and its 2-isomer, proved able to slow the rate of aging significantly.
