Synthetic strategies for 5- and 6-membered ring azaheterocycles facilitated by iminyl radicals
Abstract
The totality of chemical space is so immense that only a small fraction can ever be explored. Computational searching has indicated that bioactivity is associated with a comparatively small number of ring-containing structures. Pyrrole, indole, pyridine, quinoline, quinazoline and related 6-membered ring-containing aza-arenes figure prominently. This review focuses on the search for fast, efficient and environmentally friendly preparative methods for these rings with specific emphasis on iminyl radical mediated procedures. Oxime derivatives, particularly oxime esters and oxime ethers, are attractive precursors for these radicals. Their use is described in conventional thermolytic, microwave-assisted and UV-vis based preparative procedures. Photoredox catalyzed protocols involving designer oxime ethers are also covered. Choice can be made amongst these synthetic strategies for a wide variety of 5- and 6-membered ring heterocycles including phenanthridine and related aza-arenes. Applications to selected natural products and bioactive molecules including trispheridine, vasconine, luotonin A and rutaecarpine are included.
Citation
Walton , J C 2016 , ' Synthetic strategies for 5- and 6-membered ring azaheterocycles facilitated by iminyl radicals ' , Molecules , vol. 21 , no. 5 . https://doi.org/10.3390/molecules21050660
Publication
Molecules
Status
Peer reviewed
ISSN
1420-3049Type
Journal item
Rights
© 2016 by the author; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
Description
The author thanks EaStCHEM for financial support.Collections
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