A xanthene-based bismuthane/phosphane chelating ligand has been accessed that has enabled the synthesis of a palladium(0) bismuthane complex. The bismuthane donor proved to be hemilabile as it switched to a dangling position upon addition of O that gave a palladium(II) peroxide complex. Unlike the corresponding 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) palladium peroxide, the bismuth analogue could be employed for catalytic phosphane oxidation and oxidative phenol coupling.

The behavior of a xanthene derivative with one bismuthane and one phosphane function, Xan­(PPh2)­(BiPh2), as a ligand toward group 11 metal cations was investigated. It was found that contact with [Cu­(MeCN)4]­OTf, AgOTf, [Au­(PPh3)­OTf], in all three cases leads to a transformation of Xan­(PPh2)­(BiPh2) into a tridentate PBiP system, where a BiPh unit connects two phosphinoxanthyl moieties. In the resulting compounds, [PhBi­(Xan­(PPh2))2Cu]­OTf, 1, [PhBi­(Xan­(PPh2))2Ag]­OTf, 2, and [PhBi­(Xan­(PPh2))2AuPPh3]­OTf, 3, the metal cations are coordinated tetrahedrally by two phosphane donors, one bismuthane donor and a fourth ligand, corresponding to OTf– in case of 1 and 2, or PPh3 in the case of 3. DFT calculations in combination with NBO analysis showed that the bismuth atoms in these PBiP ligands act as σ-donors. 3 thus corresponds to the first known AuI ← BiIII complex.

XanI2 (4,5‐diiodo‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) and DBFI2 (4,6‐diiododibenzofuran) have been functionalized first with Ph2Bi units through reaction with PhLi and then with Ph2BiCl. The remaining C–I bonds were shown to undergo oxidative additions to M(PPh3)2 species (M = Pd, Ni; generated from employed [M(PPh3)4]), thus giving rise to heterometallic systems [Xan(BiPh2)Pd(PPh3)2I] (2), [Xan(BiPh2)Ni(PPh3)2I] (3), and [DBF(BiPh2)Pd(PPh3)2I] (6), where the bismuthane moieties are positioned vis‐à‐vis a d8‐MII center; treatment of 2 with AgOTf led to an exchange of the iodide ligand at the central nickel atom by a more weakly bound triflate ligand. The developed synthetic strategy can be envisioned to also provide access to combinations of such transition metal moieties with other main group entities for cooperative substrate activation.