A Cu-promoted cyclization of 2-nitrophenyl iodoacetylenes provides a direct route to a range of 2-iodoisatogens. These compounds represent useful intermediates for the late-stage elaboration of the C-I bond to furnish isatins and a range of alternative heterocyclic products.

We have developed a new strategy for preparing 2‐substituted indolone N‐oxides (isatogens) by substitution reactions with aryl‐ and alkyl‐organometallic reagents. This approach allows a range of substituents to be incorporated at a late stage and complements existing methods that necessitate their early stage incorporation during substrate preparation. Further chemistry has been found to take place at the nitrone moiety; intramolecular dipolar cycloaddition provides access to angularly fused tricyclic heterocycles. More unusually however, these compounds are prone to further addition by organozinc reagents leading to 2,2‐disubstituted 3‐oxindole products.

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2-Iodoisatogens: Versatile Intermediates for the Synthesis of Nitrogen Heterocycles. -The Cu(I)-promoted cyclization of 2-nitrophenylhaloacetylenes to 2-iodoisatogens is described. Depending on the electronic properties of the phenyl substituents catalytic or stoichiometric amounts of a Cu(I)-source are required for an efficient product formation. Further transformation of the products e.g. by cross coupling reactions or by a two-step displacement-decarboxylation sequence to 2-acylidene 3-oxindoles is examined. -(MADULI, E. J. M.; EDESON, S. J.; SWANSON, S.; PROCOPIOU, P. A.; HARRITY*, J. P. A.; Org. Lett. 17 (2015) 2, 390-392, http://dx.