The “Metallo”‐Diels‐Alder Reactions: Examining the Metalloid Behavior of Germanimines

Addition of MesN3 (Mes=2,4,6-Me3 C6 H2 ) to germylene [(NON(tBu) )Ge] (NON(tBu) =O(SiMe2 NtBu)2 ) (1) gives germanimine, [(NON(tBu) )Ge=NMes] (2). Compound 2 behaves as a metalloid, showing reactivity reminiscent of both transition metal-imido complexes, undergoing [2+2] addition with heterocumulenes and protic sources, as well as an activated diene, undergoing a [4+2] cycloaddition, or "metallo"-Diels-Alder, reaction. In the latter case, the diene includes the Ge=N bond and pi-system of the Mes substituent, which is reactive towards dienophiles including benzaldehyde, benzophenone, styrene, and phenylacetylene.