A Silylene-Stabilized Germanium Analogue of Alkynylaluminum.

In contrast to the well-developed metal acetylides, the heavier analogues of the type REEM (E=Si, Ge, Sn, Pb; M=metals) have not been reported to date. Herein, we describe the synthesis of a silylene-stabilized germanium analogue of alkynylaluminum (4) by the reaction of a silylene-stabilized digermavinylidene (3) with 0.25 equiv of (AlCp*) 4 in THF at 80 °C. The structure of 4 has been unambiguously characterized by spectroscopic analysis, X-ray diffraction analyses and DFT calculations, and features a linear AlGeGe skeleton with a Ge=Ge double bond and a polarized Ge-Al bond. Complex 4 shows excellent reactivity towards small molecules such as H 2 , CS 2 and TolNCO, and this allows for the construction of the structurally intriguing germylenyl aluminum complex (5) and the germacycles (6, 7).