Synlett 2009(19): 3206-3210  
DOI: 10.1055/s-0029-1218345
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Regiospecific Syntheses of 3-Aza-α-carbolines via Inverse Electron-Demand Diels-Alder Reactions of 2-Aminoindoles with 1,3,5-Triazines

Guoxing Xu, Lianyou Zheng, Shixue Wang, Qun Dang*, Xu Bai*
The Center for Combinatorial Chemistry and Drug Discovery, College of Chemistry and School of Pharmaceutical Sciences, Jilin University, 75 Haiwai St., Changchun, Jilin 130012, P. R. of China
Fax: +86(431)85188900; e-Mail: qdang@jlu.edu.cn; e-Mail: xbai@jlu.edu.cn;
Further Information

Publication History

Received 10 August 2009
Publication Date:
03 November 2009 (online)

Abstract

The scope of 1,3,5-triazine inverse electron-demand ­Diels-Alder (IDA) reactions was expanded to include 2-aminoindoles as productive dienophiles leading to various 3-aza-α-carbolines in excellent yields. Furthermore, the two ester groups of the IDA product were differentiated via reduction of the C4-ester to its corresponding alcohol. This new IDA reaction could be potentially applied to the synthesis of various 3-aza-mescengrincin analogues that may possess neuroprotective activities.

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HOMO energies for indole and 8a are -124.5 kcal/mol and -114.1 kcal/mol, respectively (calculated using Spartan with the B3LYP/6-31G* method).

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HOMO energies for 8a, 8b, and 8c are -114.1, -113.2, and -113.9 kcal/mol, respectively (to simplify the calculation, the free base forms were used, using Spartan with the B3LYP/6-31G* method).

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CCDC 748786 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.