Overcoming Substrate Bias in Radical Addition: Selective C3-Functionalisation of Indoles

Abstract Radical chemistry provides complementary methods to traditional 2-electron mechanisms for indole functionalisation. Radical addition of electron-poor radicals to indoles is generally C2-selective. We hereby report that this substrate bias can be overcome through installing a bulky silyl group at the indole N–H bond, leading to a strategy for selective addition of electron-poor carbon-centred radicals at the 3-position.