Figure 1: Preparation of 1,3,2,4-diazadiborinine 4.
From: 1,3,2,5-Diazadiborinine featuring nucleophilic and electrophilic boron centres

4a–c present the resonance forms.
From: 1,3,2,5-Diazadiborinine featuring nucleophilic and electrophilic boron centres

4a–c present the resonance forms.