A High Yield Synthesis of an Octastannacubane and a Bis(silyl) Stannylene via Reductive Elimination of a Silane

Thermolysis of tris(silyl) tin hydride 2 at 70 °C for 3 hours results in elimination of tBu 2 MeSiH and generation of bis(silyl) stannylene 3 which dimerizes instantaneously yielding distannene 4 . Compound 3 can be trapped by NHC Me yielding stannylene‐NHC Me complex 5 . Upon heating (70 °C, 24 h) 4 yields stannyl radical 8 along with pentastannatricyclo[2.1.0.0 2, 5 ]pentane 10 (ca. 30 %) and traces (ca. 5 %) of the novel octastannacubane 9 . Remarkably, octastannacubane 9 is produced in 70 % yield by mild heating (50 °C) of 1,1,2,2‐tetrasilyldistannane 11 , along with tBu 2 MeSiH. Octastannacubane 9 was characterized by X‐ray crystallography, NMR and UV/Vis spectroscopy. Based on DFT quantum‐mechanical calculations the 11 → 9 transformation occurs via reductive elimination of two tBu 2 MeSiH molecules from 11 yielding a distannyne, (or its bis‐stannylene isomer), followed by its tetramerization.