Boranes with Two Boron-Bonded Nitrogen Atoms

2 Boranes with Two Boron-Bonded Nitrogen Atoms 4.2.2.1 Derivatives of Amino-iminoborane, HNBNH2 

In this section, 2,2,6,6-tetramethylpiperidin-1-yl is denoted by CgHieN. For the formulation of amino-iminoboranes in the literature, see p. 210. 

The knowledge of amino-iminoboranes has increased significantly since the preparation of the first few examples of this type of compounds (see Boron Compounds 3rd Suppl. Vol. 3, 1988, p. 100), and two reviews have appeared about the chemistry of such species [1, 2]. Compounds of the general formula RN=B-NR R, which can be isolated at room temperature, are kinetically stabilized by steric protection. A survey is compiled in Table 4/9 together with the synthetic method employed and relevant NMR and v( BN) IR data. The sterically hindered amino-iminoboranes are prepared either by vacuum pyrolysis and FSi(CH3)3-elimina-tion from their fluorine-containing diaminoborane precursors in the gas phase, or by hydrogen halide elimination with bases from the corresponding diaminoborane derivatives in solution. 

The compounds, listed in Table 4/9, are prepared by the following methods  

Method IV Vacuum pyrolysis with elimination of (CH3)3SiX, where X=F, Cl. 

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