From the Dilithiooctamethylcyclotetrasilazane to the 1,3,5,7‐Tetraaza‐2,4,6,8,9‐pentasilabicyclo[3.3.1]nonane System

Reaction of the long-known cyclotetrasilzane derivative 1 was accomplished for the first time without ring-opening, namely by treatment with nBuLi to afford the dimer [2]2, in which two eight-membered rings are joined through an (LiN)2 four-membered ring. Depending on the molar ratios used, reaction of 2 with PhSiF3 results in either disubstitution or bridging to give 3.