Synthesis, structure, and reaction of tricoordinate stibine and tetracoordinate stiboranide

Tricoordinate stibine 1 and tetracoordinate stiboranide 2a were synthesized by utilizing SbCl3. The structure of 2a was confirmed by X-ray analysis. The interconversion between 1 and 2 could be achieved by BrNEt4 and NaH or BuLi. The pentacoordinate apicophilic stiborane 6 was prepared from 1. Due to steric repulsion between the TIP group and the aromatic ring, the C1–Sb–C2 angle of 6b was narrowed by 4.4° compared to that of 6a by X-ray analysis.