Transition metal complexes in organic synthesis, part 37.1 convergent iron-mediated total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C
✍ Scribed by Hans-Joachim Knölker; Wolfgang Fröhner
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- French
- Weight
- 224 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
The antioxidative agent carbazoquinocin C has been synthesized by a convergent iron-mediated construction of the carbazole nucleus using a novel one-pot C-C and C-N bond formation which is carried out in the air.
📜 SIMILAR VOLUMES
The efficient palladium-catalyzed oxidative coupling of an anilinoquinone and subsequent regioselective introduction of the heptyl side chain provide the antioxidative substance carbazoquinocin C in four steps and 36% overall yield from aniline.
Evidence for the structure of 13 was provided by the sharp s at 12.67 ppm (phenol OH) in the 'H-NMR spectrum. The substitution pattern was confirmed by NOE difference spectra. Irradiation at the Me signal at 2.28 ppm resulted in a NOE of the aromatic proton at 6.67 ppm.
þ)-Demethoxycarbonyldihydrogambirtannine was obtained in six steps and 49% overall yield from 3,4-dihydro-b-carboline using an iron-mediated [2+2+1] cycloaddition as the key-step. Oxidation of (þ)-demethoxycarbonyldihydrogambirtannine led to norketoyobyrine.