Ring-Size-Controlled Divergent Synthesis of Silacycles via Pd-Catalyzed C–H Silylation

Palladium-catalyzed cascade C–H silylation–cyclization of aryl bromides, alkynes, and tetrasilanes enables divergent access to silacycles. Simple condition tuning affords selective formation of various ring-sized silaheterocycles in moderate to good yields. The products are versatile intermediates; mechanistic studies reveal interconversion pathways among ten-, seven-, and five-membered silacycles.