Details

Autor(en) / Beteiligte

• van Loon, Amy A
• Holton, Maeve K
• Downey, Catherine R
• White, Taryn M
• Rolph, Carly E
• Bruening, Stephen R
• Li, Guanqun
• Delaney, Katherine M
• Pelkey, Sarah J
• Pelkey, Erin T

Titel

Preparation of Dibenzo[e,g]isoindol-1-ones via Scholl-Type Oxidative Cyclization Reactions

Ist Teil von

• Journal of organic chemistry, 2014-09, Vol.79 (17), p.8049-8058

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2014

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• A flexible synthesis of dibenzo­[e,g]­isoindol-1-ones has been developed. Dibenzo­[e,g]­isoindol-1-ones represent simplified benzenoid analogues of biological indolo­[2,3-a]­pyrrolo­[3,4-c]­carbazol-5-ones (indolocarbazoles), compounds that have demonstrated a wide range of biological activity. The synthesis of the title compounds involved tetramic acid sulfonates. Different aryl groups were introduced at C4 of the heterocyclic ring via Suzuki–Miyaura cross-coupling reactions. Finally, mild Scholl-type oxidative cyclizations mediated by phenyliodine­(III) bis­(trifluoroacetate) (PIFA) converted some of the latter compounds into the corresponding dibenzo­[e,g]­isoindol-1-ones. A systematic study of the oxidative cyclization revealed the following reactivity trend: 3,4-dimethoxyphenyl ≫ 3-methoxyphenyl > 3,4,5-trimethoxyphenyl > 4-methoxyphenyl ≈ phenyl. Overall, the oxidative cyclization required at least two methoxy groups distributed in the aromatic rings, at least one of which had to be located para to the site of the cyclization.