An efficient and cost-effective copper-mediated aerobic oxidative C-H iodination and nitration of indoles via double C-H functionalization is reported. The domino process proceeds smoothly under mild aerobic conditions to give 3-iodo-2-nitroindoles in one step with high regioselectivity and a broad substrate scope. The mechanism of the iodination step is proposed to proceed via a Cu(iii)-iodide species that undergoes electrophilic addition at the C3 position of the indole motif. The subsequent nitration step involves a sequence of C-H activation, nitro radical oxidative addition, and reductive elimination.

A direct C-2 methylation reaction of indoles bearing a readily removable N-2-pyrimidyl moiety as a site-specific directing group has been developed with a palladium catalyst. This reaction relied on the use of KF to promote efficient methylation. A moderate to good yield was achieved in a range of indole substrates.

A facile, one-step synthesis of annulated indoles from (N–H) indoles and dibromoalkanes was developed through a palladium-catalyzed double alkylation process.

A palladium catalyzed intramolecular C(sp2)−H amination using a readily available aluminum nitrate (Al(NO3)3·9H2O) as oxidant is reported. The C−H amination is promoted by in-situ nitration of the quinoline directing group...

In this novel and alternative route to 2‐methylindoles, the removable 2‐pyrimidyl group is preferentially used as directing group.