1.2- Diaza-3,6-diborine

With one more N-B bond, the cyclic conjugation is discontinuous in 1,3,2,4-diaza-diborine. The donors and acceptors are alternately disposed along the cyclic chain. Electrons cannot effectively delocalize in a cyclic manner, but between the adjacent donor-acceptor pairs in a non-cyclic manner. The diazadiborine is not predicted to be aromatic. 

In a recent paper, Siebert and coworkers report on the preparation and properties of l,2,3,4-tetrahydro-2,3-diaza-l,4-diborines (155) starting from thiadiboroles (Scheme 30). 

The best characterized s-diazadiborine compound is l,3-bis(trimethyl-silyl)-2,4-bis(bis(trimethylsilyl)amino)-l,3-diaza-2,4-diborine. This compound was obtained from following reactions I05,i06,i08,i74) [Eq. (46)]. 

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