A simple reaction of some oxindole derivatives with 1,2-diaza-1,3-dienes to produce 2-oxo-spiro[indole-3,4′-pyridines] in good yields is described here. This transformation represents a practical two steps approach to new and biologically interesting 2-oxo-spiro[indole-3,4′-pyridine] scaffolds using a double Michael addition/cyclization sequence.
![Graphical abstract: Synthesis of novel symmetrical 2-oxo-spiro[indole-3,4′-pyridines] by a reaction of oxindoles with 1,2-diaza-1,3-dienes](http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=C4OB01959H "Graphical abstract")
Org. Biomol. Chem., 2015,13, 277-282
DOI: 10.1039/C4OB01959H
http://pubs.rsc.org/en/content/articlelanding/2015/ob/c4ob01959h/unauth#!divAbstract
