Palladium‐Catalyzed Silacyclization of (Hetero)Arenes with a Tetrasilane Reagent through Twofold C−H Activation

The use of an operationally convenient and stable silicon reagent (octamethyl-1,4-dioxacyclohexasilane, ODCS) for the selective silacyclization of (hetero)arenes via twofold C-H activation is reported. This method is compatible with N-containing heteroarenes such as indoles and carbazoles of varying complexity. The ODCS reagent can also be utilized for silacyclization of other types of substrates including tertiary phosphines and aryl halides, rendering a diverse transformation. A series of mechanistic experiments and density functional theory (DFT) calculations were used to investigate the preferred pathway for this twofold C-H activation process.