176327-49-4Relevant academic research and scientific papers
Antioxidant effects of the hydroxy groups in the simple phenolic carbazoles
Hieda, Yuhzo,Hatae, Noriyuki,Anraku, Makoto,Matsuura, Nobuyasu,Uemura, Kazuhide,Hibino, Satoshi,Choshi, Tominari,Tomida, Hisao,Hori, Osamu,Fujioka, Haruto
, p. 120 - 132 (2016/03/01)
Antioxidant activities of the simple phenolic carbazoles 5-11 were evaluated by 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate)+ radical scavenging assays. The simple phenolic carbazoles 5-7, 9, and 11 exhibited stronger antioxidant activities than α-tocopherol, and similar antioxidant activities as phenolic carbazole alkaloids carazostatin (1), and carbazomadurins A (3) and B (4). Bond dissociation energies and highest occupied molecule orbital energy levels of a series of phenolic carbazoles including phenolic carbazole alkaloids were calculated. The reducing ability of the phenolic carbazole core could be important role for the antioxidant activity of carbazole alkaloids 1, 3, and 4.
Total Syntheses of Carazostatin, Hyellazule, and Carbazoquinocins B-F
Choshi, Tominari,Sada, Takuya,Fujimoto, Hiroyuki,Nagayama, Chizu,Sugino, Eiichi,Hibino, Satoshi
, p. 2535 - 2543 (2007/10/03)
Total syntheses of carazostatin (1), hyellazole (2a), and carbazoquinocins B-F (3b-f) have been completed. The cross-coupling reaction between 3-iodoindole 8 and vinylstannane 11b gave the 3-alkenylindole 7. Treatment of 7 with ethynylmagnesium bromide, followed by etherification of the resulting alcohol 12 with MOMCl, yielded the 3-alkenyl-2-propargylindole 6. The compound 6 was treated with t-BuOK in t-BuOH at 90°C to obtain the desired carbazoles 4 together with the N-deprotected carbazole 13 through an allene-mediated electrocyclic reaction. The carbazole 13a, derived from 4a or 4c, was converted into the triflate 24 in two steps. The triflate 24 was subjected to the Suzuki cross-coupling reaction with either 9-heptyl-9-BBN or phenylboronic acid in the presence of a palladium catalyst to produce the 1-heptylcarbazole 25a and the 1-phenylcarbazole 25b. Cleavage of the ether bond of 25a yielded carazostatin (1). Cleavage of the ether bond of 25b followed by O-methylation gave hyellazole (2a). Oxidation of carazostatin (1) with benzene seleninic anhydride afforded carbazoquinocin C (3c). In a similar way, carbazoquinocins B and D-F (3b,d-f) were synthesized, respectively.
Total synthesis of carazostatin and hyellazole by allene-mediated electrocyclic reaction
Choshi,Sada,Fujimoto,Nagayama,Sugino,Hibino
, p. 2593 - 2596 (2007/10/03)
The free radical scavenger carazostatin and the marine alkaloid hyellazole have been synthesized by a new type of allene-mediated electrocyclic reaction involving the indole 2,3-bond as a key step.
