New air stable diarylamino substituted diborane(4) derivatives: Synthesis and structures

In recent years, the rekindled interest in B/N ring systems has led to a plethora of novel compounds with varying substitution patterns. Diaminodiboranes are the starting compounds for the preparation of many boron compounds such as diborane derivatives, used for many addition and insertion reactions into multiple bonds in the literature, however there are few air-stable diborane(4) derivatives. In this study, to synthesize new air-stable B,B'-diaryl and bis(dimethylamino)-B,B'-diarylaminodiboranes(4), the bulky amines were selected. These derivatives were prepared through the reaction of lithium anilide derivatives and 1,2-dichlorodiboranes. The structures of the compounds were characterized by using nuclear magnetic resonance (NMR) spectroscopy. The crystal and molecular structures of 3ae, 3af, 3bb, 3be, 3ce, 3cd and 3cf were determined using the single-crystal X-ray diffraction technique. X-ray diffraction studies have showed that the diarylamino group in the solid state is nearly orthogonal to the plane due to the boron-bound bulky groups.