Regio- and Chemoselective Access to Borylmethyl-Substituted Silacyclobutanes via Copper-Catalyzed Borylative Cyclization

Silacyclobutanes (SCBs) are pivotal synthons for constructing complex organosilicon architectures; however, synthetic routes to β-functionalized SCBs remain underexplored. Herein we report a novel Cu(I)-catalyzed borylative cyclization strategy that enables regio- and chemoselective synthesis of β-functionalized SCBs from silicon-tethered alkenyl chlorides and bis(pinacolato)diboron. This method provides a scalable approach for the construction of diverse borylmethyl-substituted silacyclobutanes under mild conditions. The installed boronate moiety serves as a versatile synthetic handle for accessing complex silicon-containing heterocycles, demonstrating significant utility in organosilicon chemistry.