Synthesis of Unnatural Arundines Using a Magnetically Reusable Copper Ferrite Catalyst

Abstract

We report a method for copper ferrite-catalyzed coupling of indoles and N,N-dimethylacetamide (DMA) to afford Arundine derivatives. Halogen, methoxy, boronate ester, and trimethylsilyl functionalities are compatible with reaction conditions. Unprotected or sterically hindered indoles are also competent substrates. Indoles containing competitively reactive pyrazoles deliver the desired products in reasonable yields. The copper ferrite is easily recovered and reused, up to nine times without a significant yield loss.

Key words

copper ferrite - C–H functionalization - indoles - Arundine - dimerization

• References and Notes

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• 12 We also attempted N-methyl-7-azaindole; however, no product formation was observed. See the Supporting Information for a list of unsuccessful substrates.