Rhodium‐Catalyzed Intermolecular Silylation of Csp‐H by Silacyclobutanes

The signature reactivity of silacyclobutane (SCB) is their cycloaddition reactions with various π bonds. Recently, the first cases were disclosed where SCBs reacted with both Csp2 -H and Csp3 -H σ bonds in an intramolecular fashion. Herein, it is reported that SCB is also an efficient reagent for Csp -H bond silylation. Thus, rhodium-catalyzed intermolecular reactions between SCBs and terminal alkynes produced a series of symmetrical and unsymmetrical tetraorganosilicons bearing a Csp -Si functionality. Preliminary studies suggested that the reaction did not involve a cycloaddition pathway, but instead a direct activation of Csp -H bonds.