Abstract
A practical process for the synthesis of 2-unsubstituted indoles
and azaindoles has been developed by the palladium-catalyzed direct
annulation of electron-poor o -chloro/bromoanilines and o -chloroaminopyridines with aldehydes.
Coupled with the previous results of Jia and Zhu, this allows rapid
access to a variety of 2-unsubstituted indoles and azaindoles starting
from simple and easily accessible precursors.
Key words
indole - azaindole - palladium - annulation - ligand
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indole in 55 and 70% yield, respectively. Reaction of 2-chloro-5-methoxyaniline with
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¹ H NMR (300 MHz, CDCl3 ): δ = 8.08
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