Correction for ‘Catalytic enantioselective construction of quaternary stereocenters by direct vinylogous Michael addition of deconjugated butenolides to nitroolefins’ by Madhu Sudan Manna et al., Chem. Commun., 2012, 48, 5193–5195.
By combining an iron-catalyzed borrowing hydrogen of allylic alcohols with an enantioselective organocatalyzed Michael addition of β-keto esters followed by a subsequent DBU-promoted lactonization different enantioenriched δ-lactones have been synthesized with good enantioselectivities. The valuable building blocks, featuring in some cases challenging quaternary stereocenters, have been obtained with >90% ee.
An efficient organocatalytic vinylogous Michael addition-triggered quadruple cascade reaction resulting in fused spiroxindoles bearing multiple quaternary stereocenters is demonstrated from β-trifluoroacetylarylidene indanediones and 3-alkylideneoxindoles.