A photoexcited halogen-bonded EDA complex of the thiophenolate anion with iodobenzene for C(sp3)-H activation and thiolation

Chem Sci. 2021 Oct 21;12(47):15655-15661. doi: 10.1039/d1sc03667j. eCollection 2021 Dec 8.

Abstract

Thiophenol was discovered to form an EDA complex with iodobenzene through halogen bonding interactions upon treatment with KOH. A direct photochemical thiolation of C(sp3)-H bond-containing etheric, allylic, and benzylic substrates with thiophenol was developed. The reaction proceeded on the basis of the in situ generation of a thiyl radical and aryl radical through single electron transfer between the photoexcited thiophenolate anion and aryl iodide EDA complex. Then a C(sp3) centred-radical was formed by aryl radical-mediated hydrogen atom transfer and the thiolation products were delivered via a radical-radical cross-coupling with the thiyl radical.