Brønsted acid-promoted C–F bond activation in [P,S]-ligated neutral and anionic perfluoronickelacyclopentanes†
Treatment of L2Ni(CF2)44a–c (L = PPh3, PPh2Me, pyridine) with an external Lewis acid (trimethylsilyl triflate) gives new L-functionalized fluoronickelacyclopentanes 5a–c. Complexes L2Ni(CF2)44a,b react with the thiol form of the bidentate ligand 1,2,4-(HS)(Ph2P)Me(C6H3) [P,SH] through a unique Brønsted acid-promoted Cα–F bond activation mechanism, affording phosphine-functionalized nickelacycles bearing a phosphinothiolate ligand 6a–b. Furthermore, substituting monodentate ligands in L2Ni(CF2)44a–c with the deprotonated form of the bidentate ligand [P,S−] leads to the first anionic perfluoronickelacycle 7. The anionic metallacyle reacts with phosphonium salts [PHPh3](Br) and [PHPh2Me](Br) to yield HF and phosphine-functionalized nickelacycles 6a,b that still contain the terminal thiolate moiety.
- This article is part of the themed collection: Fluorine