Organometallic Diaza‐dimetalla‐Norbornanes and ‐Cyclohexanes of Aluminium,Gallium and Indium

Selective formation of 1,3,3,4,6,6‐hexamethyl‐1,4‐diaza‐3,6‐diinda‐norborane was achieved by the reaction of bis(lithiomethyl‐methylamino)methane with dimethylindium chloride by simultaneous formation of two dative metal‐carbon and two metal‐nitrogen bonds accompanied by two ring closures. The synthesis of heterometallic compounds of this type, namely 1,3,3,4,6,6‐hexamethyl‐3‐alumina‐1,4‐diaza‐6‐galla‐norborane [Me₂AlCH₂N(Me)]CH₂[N(Me)CH₂GaMe₂], was also attempted by the reaction of bis(lithiomethyl‐methylamino)methane with dimethylaluminium and ‐gallium chloride. This compound is formed, but cannot be separated from the simultaneously formed homometallic compounds [Me₂MCH₂N(Me)]₂CH₂(M = Al, Ga). The compounds were identified by elemental analyses, mass spectra, NMR spectroscopy (¹H, ¹³C), and by determination of their crystal structures in which they are present as monomers. The norbornane‐like structure is favoured over potential isomers containing three‐membered rings and over polymeric aggregation in both compounds. In addition, the crystal structure of dimethyl(dimethylaminomethyl)indium was determined by single crystal X‐ray diffraction, which shows an intermolecular aggregation into a six‐membered ring dimer.