Bis(haloboryl)amines (I; R = Me, Et, Me2CH, Me3C; R1 = Me, Et, Me2CH, MeCHEt, Me3C, Cl, Me2N; R2 = CHMe2, CMe3, SiMe3; X = Cl, Br) were prepd. from RB.tplbond.NR2 and R1BX2. Redn. of I by Li gave nido-diazahexaboranes, and in some cases azadiboriridines (II) were intermediates. Ring expansion of II by 3-hexyne and by EtB.tplbond.NCMe3 gave azadiborolines, e.g., III, and a diazatriborolidine (IV), resp. III were reduced by Li to di-Li azadiborolinates. X-ray analyses were described.