Silylpalladium Cations Enable the Oxidative Addition of C(sp3)–O Bonds

The synthesis and characterization of the room-temperature and solution-stable silylpalladium cations (PCy3)2Pd–SiR3+(C6F5)4B– (SiR3 = SiMe2Et, SiHEt2) and (Xantphos)Pd–SiR3+(BArf4) (SiR3 = SiMe2Et, SiHEt2; Xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene; BArf4 = (3,5-(CF3)2C6H3)4B–) are reported. Spectroscopic and ligand addition experiments suggest that silylpalladium complexes of the type (PCy3)2Pd–SiR3+ are three-coordinate and T-shaped. Addition of dialkyl ethers to both the PCy3 and Xantphos-based silylpalladium cations resulted in the cleavage of C(sp3)–O bonds and the generation of cationic Pd–alkyl complexes. Mechanistically enabling is the ability of silylpalladium cations to behave as sources of both electrophilic silylium ions and nucleophilic LnPd(0).