Photocatalyzed Oxycarboranylation of Alkenes with 1-Iodo-<i>o</i>-carboranes through a Halogen-Atom Transfer Strategy

Carboranes are of growing importance to pharmaceutical chemistry as the key units of boron neutron capture therapy (BNCT) reagents and the three-dimensional analogue of benzene. Light-induced functionalization of carboranes is a powerful tool for constructing carborane-containing compounds. However, in comparison to the various methods forming boron-centered carboranyl radicals, those for carbon-centered carboranyl radicals are limited to the direct absorption of light energy through carborane, which is a challenge for substrate accessibility and diversity transformations. Here, we reported a method for the generation of electrophilic carbon-centered carboranyl radicals by a polarity-matched halogen-atom transfer (XAT) process and their transformation with alkenes to afford alcohols. The practicality of this protocol was emphasized by the late-stage functionalization of drugs and natural products. Mechanistic studies elucidated that fast and efficient generation of carbon-centered carboranyl radicals through nucleophilic radical abstractors is crucial.