Light-Promoted Dearylation of Perfluorinated Aryl Sulfides with N-Heterocyclic Carbene-Borane

The removal of the tetrafluoropyridinyl group tethered to a sulfur atom using a complex of N-heterocyclic carbene (NHC) with borane is described. The reaction is performed under blue light irradiation with a disulfide as radical initiator. The selective cleavage of S-Ar in preference to the weaker S-Alk bond is achieved as a result of aromatic radical substitution of the thiyl group by a NHC-stabilized boron-centered radical. Alkyl thiols, which are the primary products of the dearylation, are in situ oxidized or alkylated, affording disulfides or sulfides, respectively.

Automated summary

This study presents the removal of a tetrafluoropyridinyl group tethered to a sulfur atom using a complex of N-heterocyclic carbene (NHC) with borane. The reaction is carried out under blue light irradiation with a disulfide as a radical initiator. Selective cleavage of S-Ar bond rather than the weaker S-Alk bond is achieved through aromatic radical substitution of the thiyl group by a NHC-stabilized boron-centered radical. Alkyl thiols, the primary products of dearylation, can be in situ oxidized or alkylated to form disulfides or sulfides, respectively.