Copper-Catalyzed C-H Activation to Polysubstituted Indoles

Significance

A copper-catalyzed synthesis of polysubstituted indoles from N-aryl enaminones is reported involving an intramolecular aryl C-H activation/C-C bond formation sequence. Under optimized conditions, a large number of substituted N-aryl enaminones were converted into the corresponding indoles with moderate to good yields. The reaction was also carried out in situ by addition of primary amines to α,β-ynones without isolation of the enaminone intermediates. A mechanism was proposed on the basis of preliminary evidence.