The "Metallo"‐Diels–Alder Reactions: Examining the Metalloid Behavior of Germanimines.

Addition of MesN3 (Mes=2,4,6‐Me3C6H2) to germylene [(NONtBu)Ge] (NONtBu=O(SiMe2NtBu)2) (1) gives germanimine, [(NONtBu)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 π‐system of the Mes substituent, which is reactive towards dienophiles including benzaldehyde, benzophenone, styrene, and phenylacetylene. [ABSTRACT FROM AUTHOR]