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Versatile Base‐Catalyzed Route to Polycyclic Heteroaromatic Compounds by Intramolecular Aza‐Michael Addition
Author(s) -
Bandini Marco,
Eichholzer Astrid,
Monari Magda,
Piccinelli Fabio,
UmaniRonchi Achille
Publication year - 2007
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200601139
Subject(s) - chemistry , intramolecular force , regioselectivity , michael reaction , catalysis , ring (chemistry) , derivative (finance) , combinatorial chemistry , stereochemistry , organic chemistry , financial economics , economics
Abstract A catalytic new synthetic approach to 3,4‐dihydropyrazino[1,2‐ a ]indol‐1(2 H )‐ones by intramolecular 1,4‐addition of readily available α,β‐unsaturated esters, is described. Here, the use of a range of organic as well as inorganic bases (5–10 mol‐%) allowed a fast (30 min) and regioselective ring‐closing reaction to be performed in high yields under simple operational conditions. Moreover, the protocol was effectively employed, as the key step, in the synthesis of the dibromopyrrolo alkaloid derivative N ‐Bn‐longamide b.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)