Synthesis of Gold(I) Complexes Bearing Verkade's Superbases

International audienceProazaphosphatranes, also known as Verkade's superbases, have been investigated as ligands for gold(I). If the coordination to the gold center by the phosphorus atom suggests phosphine‐like behavior, gold(I)‐containing Verkade's superbase complexes could also be prepared from the weak conjugate acid azaphosphatrane by the formation of the corresponding silver complex and subsequent transmetalation to gold, similarly to the synthetic route used for complexes bearing N‐heterocyclic carbene ligands (NHCs). A competitive transmetalation experiment highlighted the higher lability of Verkade's superbases compared with NHCs. Furthermore, combined theoretical and experimental studies showed that they display strong σ‐donor ability, better than phosphines and similar to NHCs. Thus, some specific properties of both NHCs and phosphines are combined in Verkade's superbases, thereby providing a new approach to tuning the ligand properties of gold(I) complexes