Base-Catalyzed C(sp)-H Bond Silylation With Silacyclobutanes

Alkynylsilanes are versatile building blocks in organic synthesis and materials science, yet their direct synthesis via C(sp)-H silylation remains challenging due to the frequent requirement for precious-metal catalysts or hydrosilane reagents. Herein, we report a base-catalyzed intermolecular C(sp)-H bond silylation of terminal alkynes using silacyclobutanes (SCBs) as silicon sources, representing a fundamentally distinct strategy from previously reported transition-metal-mediated processes. Enabled by catalytic LiHMDS under mild conditions, this protocol proceeds efficiently at room temperature without the involvement of Rh or other noble metals. Notably, the reaction operates through C─Si bond cleavage of the strained silacyclobutane, rather than Si-H activation or metal insertion pathways, thereby circumventing competitive hydrosilylation and hydrogen evolution. Good functional-group tolerance, excellent chemoselectivity, and gram-scale applicability further highlight the practicality of this transformation. Preliminary mechanistic studies indicate that C(sp)─H bond cleavage is not involved in the rate-determining step.