Details

Autor(en) / Beteiligte

• Tong, Shuo
• Xu, Zhengren
• Mamboury, Mathias
• Wang, Qian
• Zhu, Jieping

Titel

Aqueous Titanium Trichloride Promoted Reductive Cyclization of o-Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine

Ist Teil von

• Angewandte Chemie (International ed.), 2015-09, Vol.54 (40), p.11809-11812

Auflage

International ed. in English

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Treatment of o‐nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)–H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β‐disubstituted o‐nitrostyrenes, 2,3‐disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of aspidospermidine. Mild and efficient treatment of o‐nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)–H amination process. A concise synthesis of a marketed drug (rizatriptan) and a formal total synthesis of aspidospermidine featuring this novel N‐heterocyclization process are reported.