P-Directed and Lewis Acid-Assisted Pd-Catalyzed Si─Me Bond Activation Enabling Alkyl Exchange at Silicon.

A novel mode of Si─Me bond activation has been unveiled through the cooperative action of a P-directing group, a palladium catalyst and a Lewis acid. The pivotal role of the Lewis acid in enabling the activation of the strong and low-polarity Si─Me bond was elucidated via stoichiometric experiments. According to DFT calculations, the Lewis acid acts as a Me- acceptor and triggers the formation of the key cationic silyl Pd complex responsible for the alkyl exchange at Si. This unprecedented Si─Me bond transformation has been demonstrated in a four-step sequence, enabling the stepwise upgrading of Me3SiCl into silanols bearing diverse organic substituents.