Gold‐Catalyzed Synthesis of 5H‐Benzo[b]indeno[2,1‐d]silines by Insertion of Vinyl Carbocations into the Si–H Bond

We have developed a gold‐catalyzed cascade reaction of aryldiynes bearing a hydrosilyl group to afford a variety of unexplored 5H‐benzo[b]indeno[2,1‐d]silines. The reaction system is applicable to the synthesis of bidirectionally π‐extended silacycles from tetra(alkynyl)aryl compounds. Computational studies suggest that 5H‐benzo[b]indeno[2,1‐d]silines are formed via the insertion of a vinyl carbocation intermediate into the Si–H bond.