Copper-mediated domino C–H iodination and nitration of indoles†
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.