Activation of the GaI Cation for Bond Activation: from Oxidative Additions into C−Cl and H−P Bonds to Reversible Insertion into P4

Abstract

AbstractAlthough the discovery of the GaI complex salt [Ga(PhF)2‐3][Al(ORF)4] (RF=C(CF3)3, PhF=C6H5F) invoked the preparation of a diverse library of cationic Ga(I) coordination complexes and clusters, studies on small molecule activation with low‐valent GaI cations are scarce. Herein, a first experimental study on the reactivity of a monomeric Ga(I) cation activated with a pyridine–diimine pincer ligand (in [Ga(PDIdipp)][Al(ORF)4]) towards small‐molecules is reported. First controlled oxidative additions of the GaI cation into C−Cl, H−P and P−P bonds are presented. Moreover, the [4+1]cycloaddition to butadienes was achieved. Intriguingly, the isolated, blue insertion product into the P−P bond of P4 allows for the quantitative release of the P4 molecule upon reaction with AlEt3 and butadienes. Reversible P4 insertion of main‐group metals has previously been reported for Ge and Sn, respectively. The experimental study is supported by high‐level computational analysis of the in‐part reversible oxidative additions at the DLPNO‐CCSD(T)/def2‐TZVPP//PBEh‐3c/def2‐mSVP level of theory with COSMO‐RS solvation in 1,2‐difluorobenzene.