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features good functional group tolerance and broad substrate scope.
In addition, the directing group can be easily deprotected to generate
1,2-dicarbonylated arenes, which provides the possibility for further
transformation into synthetically valuable compounds like lactones.
Intriguingly, when N-monosubstituted oxamic acids are employed as
the substrates, the formed ortho-amidated ketoximes can undergo
further intramolecular cyclization to produce biologically active
3-methyleneisoindolinones.
Conflicts of interest
There are no conflicts to declare.
Notes and references
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A similar cyclization process for the formation of 3-methylene-
isoindolinones was proposed for the Rh-catalyzed amidation
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simplest oxamic acid H2NCOCO2H was also attempted for the
ortho-amidation, yet no desired product could be obtained,
probably due to that the primary aminoacyl radical was difficult
to generate under our conditions.
In conclusion, we have developed the first palladium-catalyzed
decarboxylative ortho-amidation of O-methyl ketoximes by using
readily available, easy to handle and environment-friendly N,N-
disubstituted oxamic acids as the amidation sources. This procedure
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12554 | Chem. Commun., 2019, 55, 12551--12554
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