Iron-Catalyzed Regioselective Silylation of 1,3-Dienes to Access Multifunctional Allylic Polysilanes.

Allyl trisilylanes, as synthetically accessible surrogates of allylic trimetallic reagents, may play a pivotal role in organic synthesis, particularly in transition-metal-catalyzed transformations and the construction of complex molecular architectures. Herein, we report an iron-catalyzed trisilylation of 1,3-diene electrophiles bearing an SMe leaving group, providing efficient access to allylic trisilanes with high efficiency and excellent regioselectivity. Mechanistic studies reveal that the iron-catalyzed trisilylation proceeds via a sequential Fe-Si migratory insertion/β-SMe elimination pathway. This protocol not only provides a practical route to multifunctionalized allylic polysilanes, but also offers fundamental insights into the development of transformations involving distinct reactivity profiles of iron-silyl species.