The Role of Ligands in Oxidative Addition Chemistry of Low-Valent Main Group Derivatives: Not Only Stabilization but Also Activation

At present, the use of low-valent derivatives of the main group elements, including metallylenes, etc., in catalysis as an alternative to transition metals is widely discussed. The high reactivity of these compounds often requires their stabilization by using electron-pair donor ligands. The influence of the latter on oxidative addition reactions is usually not considered. In this work, to the best of our knowledge for the first time, using the example of the oxidative insertion of Lappert's germylene into PhSSPh in the presence of N, S, P, and O donor ligands, we show that the ligands significantly increase the reaction rate. This can be associated with an increase in the level of the germylene highest occupied molecular orbital under the influence of a donor. Qualitatively, the obtained values of the reaction rate constants correlate well with the germylene oxidation potentials in the presence of ligands or ligand oxidation potentials.