Palladium-catalyzed syntheses of tetrahydrocarbazolones as advanced intermediates to carbazole alkaloids
摘要:
Two sequential palladium-catalyzed reactions, an intermolecular Stille cross-coupling followed by a recently developed palladium-catalyzed reductive N-heteroannulation, have been employed as the key synthetic steps toward six tetrahydrocarbazolones. The products are advanced intermediates toward a number of naturally occurring carbazole alkaloids. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis of Optically Pure Clausenamine-A and its Demethoxylated Analogs
作者:Guoqiang Lin、Aimin Zhang
DOI:10.1016/s0040-4020(00)00634-7
日期:2000.9
total synthesis of Clausenamine-A (3) was developed involving the Suzuki cross-coupling and oxidativecoupling reaction. The synthesis of its demethoxylated analogs 1 and 2 were also reported. Resolution of (+)-1, (+)-2, (+)-3 and (−)-1, (−)-2, (−)-3 were performed via their corresponding camphorsulfonates of the racemates. The absolute configurations of (+)-1, (+)-2, (+)-3 and (−)-1, (−)-2, (−)-3 were
Total synthesis of diverse oxygenated carbazoles by modified aromatization using molecular iodine
作者:Vivek T. Humne、Mahavir S. Naykode、Monica H. Ghom、Pradeep D. Lokhande
DOI:10.1016/j.tetlet.2016.01.002
日期:2016.2
A convenient route has been developed for mono and dioxygenated carbazole alkaloids from 1-oxotetrahydrocarbazoles. The key step of the synthetic route is the aromatic process of 1-oxotetrahydrocarbazoles using molecular iodine. To our knowledge, this is the first report to manifest a direct synthesis of clausine E, mukonine, mukoeic acid and mukoline, from readily available ester-containing building
A novel CAN-SiO2-mediated one-pot oxidation of 1-keto-1,2,3,4-tetrahydrocarbazoles to carbazoloquinones: Efficient syntheses of murrayaquinone A and koeniginequinone A
作者:Suchandra Chakraborty、Gautam Chattopadhyay、Chandan Saha
DOI:10.1002/jhet.561
日期:2011.3
1‐keto‐1,2,3,4‐tetrahydrocarbazoles (1) to carbazole‐1,4‐quinones (2) are efficiently carried out by CAN‐SiO2‐mediated reaction. This generalized protocol was successfully extended to the synthesis of two naturally occurring carbazoloquinones: murrayaquinone A (2b) and koeniginequinone A (2g). A plausible mechanism for this novel reaction involves formation of a 9‐hydroxy‐2,3,4,9‐tetrahydro‐1H‐carbazole‐1‐one
The first synthesis of optically pure biscarbazoles and determination of their absolute configurations
作者:Guoqiang Lin、Aimin Zhang
DOI:10.1016/s0040-4039(98)02346-6
日期:1999.1
Opticallypure dimeric O-demethylmurrayafoline A (1) and its 6,6′-dimethoxyl analog 2 were synthesized via the resolution of their corresponding camphorsulfonates of the racemates. The absolute configurations of (+) -1, (+) -2 and (−) -2 were assigned as (a R) and (a S), respectively, by the X-ray analysis and CD spectrum.
Clausenol and clausenine—two carbazole alkaloids from Clausena anisata
作者:A. Chakraborty、B.K. Chowdhury、P. Bhattacharyya
DOI:10.1016/0031-9422(95)00047-b
日期:1995.9
Two new carbazole alkaloids, designated as clausenol and clausenine, were isolated from an alcoholic extract of the stem bark of Clausenaanisata. Their structures were established as 1-hydroxy-6-methoxy-3-methylcarbazole and 1,6-dimethoxy-3-methyl carbazole, respectively, from physical and chemical evidence and synthesis. Clausenol was found to be active against Gram-positive and Gram-negative bacteria