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

Org Lett. 2022 Nov 25;24(46):8559-8563. doi: 10.1021/acs.orglett.2c03585. Epub 2022 Nov 9.

Abstract

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.