Synthese, Struktur und Reaktivität von 2-Amino- und 2-Imino-2,3-dihydro-1H-1,3,2-diazaborolen / Synthesis, Structure and Reactivity of 2-Amino- and 2-Imino-2,3-dihydro-1H-1,3,2-diazaboroles

The 2-halo-2,3-dihydro-1H-1,3,2-diazaboroles (1a′: R = tBu, X = Br; 1b: R = 2,6-Me 2 C 6 H 3; X = I) were converted into the 2-amino-2,3-dihydro-1H-1,3,2- diazaboroles (2a: R = tBu; 2b: 2,6-Me 2 C 6 H 3 ) by treatment with dry gaseous ammonia. Similarly reaction of 1a′ with 2,6-dimethylaniline or tBuNH 2 afforded the corresponding derivates (3; R 1 = 2,6-Me 2 C 6 H 3 ; 4; R 1 = tBu). The treatment of 1a′ with the ethylene diamine adduct of lithium acetylide led to the formation of (5). Lithiation of 2 a and subsequent silylation gave 6 (R 1 = SiMe 3 ), which was transformed to the diborolylamine (7) upon exposure to 1a′. Borolylketimine (8 ) and borolylcarbodiimide (9) resulted from 1a′ and Ph 2 C=NSiMe 3 or Me 3 SiN=C=NSiMe 3 , respectively. All the new compounds were characterized by elemental analyses as well as spectroscopic data (IR, 1 H, 11 B, 13 C NMR, MS). Heterocycle 5 was also subjected to an X-ray diffraction analysis.