- Total Synthesis of (+)-Aspidospermidine
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A facile asymmetric total synthesis of (+)-aspidospermidine has been developed, which is accomplished in 11 steps in an overall yield of 9.6%. Key steps involve a palladium-catalyzed enantioselective decarboxylative allylation to install the quaternary ca
- Xu, Hongjin,Huang, He,Zhao, Cui,Song, Chuanjun,Chang, Junbiao
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supporting information
p. 6457 - 6460
(2019/09/06)
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- Concise total synthesis of (±)-aspidospermidine
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(±)-Aspidospermidine (1) has been synthesized from the commercially available 2,3-dihydro-1H-carbazol-4(9H)-one 6 in 10 steps with 20% overall yield. The key step of the strategy is a one-pot carbonyl reduction/iminium formation/intramolecular conjugate addition reaction that may be applied for the synthesis of other Aspidosperma alkaloids. This journal is
- Ma, Haichen,Xie, Xingang,Jing, Peng,Zhang, Weiwei,She, Xuegong
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p. 5255 - 5259
(2015/05/13)
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- Enantioselective total synthesis of (-)-limaspermidine and formal synthesis of (-)-1-acetylaspidoalbidine
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Evolution of the synthetic strategy that culminated in the first asymmetric total synthesis of the Aspidosperma alkaloid limaspermidine is described. The successful enantioselective route to (-)-limaspermidine proceeds in 10 steps and with the isolation of only six intermediates using a Pd-catalyzed enantioselective decarboxylative allylation we have recently developed. This first enantioselective synthesis of (-)-limaspermidine establishes unambiguously its absolute configuration and allows the first asymmetric formal total synthesis of the Aspidoalbine alkaloid (-)-1-acetylaspidoalbidine.
- Zhang, Shao-Xiong,Shen, Xiao-Lei,Li, Ze-Qian,Zou, Li-Wei,Wang, Feng-Qun,Zhang, Hong-Bin,Shao, Zhi-Hui
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supporting information
p. 11444 - 11449
(2013/12/04)
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- Total synthesis of the indole alkaloid (±)- and (+)-methyl N-decarbomethoxychanofruticosinate
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All caged up: The first total synthesis of N- decarbomethoxychanofruticosinate (see figure) is achieved by using a SmI 2-mediated intramolecular Reformatsky-like reaction to create the seven-membered ring, and an intramolecular oxidative coupling to install the caged and strained ring system. Copyright
- Wei, Yi,Zhao, Duo,Ma, Dawei
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supporting information
p. 12988 - 12991
(2014/01/06)
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- Studies on the enantioselective synthesis of carbazolones as intermediates in aspidosperma and kopsia alkaloid synthesis
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Two strategies for the assembly of homochiral carbazolones have been investigated. The first exploited desymmetrisation of 1,3-cyclohexadione derivatives however this failed to deliver satisfactory outcomes. An orthogonal route exploiting palladium catalysed decarboxylative allylation of racemic carbazolone β-ketoesters has been developed. Herein we report full details on the development of this reaction and clarify apparent discrepancies between our preliminary reports and those of Shao.
- Gartshore, Christopher J.,Lupton, David W.
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p. 882 - 890
(2013/09/12)
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- Total synthesis of (±)-kopsihainanine A
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Going all the way: The first total synthesis of (±)-kopsihainanine A has been achieved in ten steps with a 12 % overall yield from commercially available 1,2,3,4-tetrahydrocarbazol-4-one (see scheme). This synthesis features an intramolecular conjugate addition of the iminium ion formed in situ with the amide and a substrate-controlled diastereoselective α-hydroxylation. Furthermore, ring D is formed by a late-stage transannular SN2 reaction. Copyright
- Jing, Peng,Yang, Zhen,Zhao, Changgui,Zheng, Huaiji,Fang, Bowen,Xie, Xingang,She, Xuegong
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scheme or table
p. 6729 - 6732
(2012/07/28)
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- New 1,2,3,9-tetrahydro-4H-carbazol-4-one derivatives: Analogues of HEAT as ligands for the α1-adrenergic receptor subtypes
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With the aim to develop new ligands able to discriminate among the three subtypes of α1-adrenergic receptors (α1A-AR, α1B-AR, and α1D-AR), a series of new 1,2,3,9-tetrahydro-4H-carbazol-4-ones bearing a 3-[[[2-(4-hydroxyphenyl)ethyl]amino]methyl] or a 3-[[4-(2-substitutedphenyl)piperazin-1-yl]methyl] side chain were synthesized. The general structure of the new compounds is reminiscent of HEAT and RN5, two potent α1-AR antagonists which show high affinities for all three α1-AR subtypes. Some derivatives in which one ring of the tetrahydrocarbazolone system was opened were also prepared. Compounds were tested in radioligand binding assays on human cloned α1A-AR, α1B-AR, and α1D-AR subtypes stably expressed in HEK293 cells. They showed moderate to good affinities, although their selectivity among the receptor subtypes hardly reached one order of magnitude.
- Romeo, Giuseppe,Materia, Luisa,Pittala, Valeria,Modica, Maria,Salerno, Loredana,Siracusa, Mariangela,Russo, Filippo,Minneman, Kenneth P.
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p. 5211 - 5219
(2007/10/03)
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- Concise and efficient synthesis of calothrixin B
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A convergent synthesis of the naturally occurring alkaloid Calothrixin B is presented, which used a regioselective hetero-Diels-Alder reaction between a "push-pull" 2-aza-diene and a N-protected 3-bromo-9H-carbazole-1,4- dione to construct the five-ring skeleton of the molecule. Protection of the indole motif with a benzyl group was unattractive for delivery of sufficient target material because the removal of the protecting group had not been high yielding. We therefore elected to temporarily protect the indole motif with a more labile benzyloxycarbonyl group. Accordingly, the synthesis of calothrixin B proceeded in 17% overall yield over 9 steps from the commercially available 1,2,3,9-tetrahydro-4H-carbazol-4-one.
- Sissouma, Drissa,Maingot, Lucie,Collet, Sylvain,Guingant, Andre
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p. 8384 - 8389
(2007/10/03)
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- A synthesis of calothrixin B
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A new short and efficient synthesis of calothrixin B is reported. The key reaction is a hetero-Diels-Alder reaction between 3-bromo-9H-carbazole-1,4-dione and a 'push-pull' 2-aza-1,3-diene.
- Sissouma, Drissa,Collet, Sylvain C.,Guingant, André Y.
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p. 2612 - 2614
(2007/10/03)
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- AMINOALKOXY CARBAZOLES FOR THE TREATMENT OF CNS DISEASES
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The present invention provides aminoalkoxy carbazole derivatives, and more specifically, provides compounds of formula (I) wherein R 1, R 2, R 3, R 4, R 8 and R 9 are described herein. These compounds are 5-HT ligands, and are useful for treating diseases wherein modulation of 5-HT activity is desired.
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- Efficient photochemical synthesis of tricyclic keto-indoles
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Tricyclic keto-indoles were synthesized by photocyclization of easily obtained enaminones in an electrocyclic photochemical reaction. The three methods reported were chosen according to the enaminone structure. The most general procedure using one-step synthesis was carried out in a benzene-methanol solution in the presence of sodium methylate. In the case of base sensitive substrates, the best method was photocyclization followed by oxidation. Besides, N-unsubstituted indoles with a five-membered ring were prepared by a photolysis reaction. All three methods are efficient and easy to perform.
- Tietcheu, Christele,Garcia, Christophe,Gardette, Daniel,Dugat, Denise,Gramain, Jean-Claude
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p. 965 - 973
(2007/10/03)
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