1,2‐Diaza‐3,5‐diborolidine CH2BR1‐(NR2)2‐BR1: Potentielle Vorstufen zu cyclischen Diborylcarben‐Liganden

摘要: The reaction of the aminohaloboranes (Me2N)(R)BX (1) (a: R = Ph, X Cl; b: Me, Br; c: iPr, Cl) with di-Grignard reagent (BrMg)2CH2 in ethyl ether/benzene mixtures afforded diborylmethanes [(Me2N)(R)B]2CH2 (2) Ph; Me; iPr), which were subsequently converted into corresponding bis(chloroboryl)methanes [(Cl)(R)B]2CH2 (3) iPr). Base-assisted cyclocondensation 3a–c 1,2-diisopropylhydrazine 1,2-diisopropyl-1,2-diaza-3,5-diorgano-3,5-diborolidines (4) Derivative 4a was deprotonated by potassium bis(trimethylsilyl)amide to give (1,2-diisopropyl-1,2-diaza-3,5-diphenyl-3,5-diborolidinyl)potassium (5). Attempts introduce a halogen atom carbon bridge between two boron treating 5 either iodine or 1,2-dibromoethane failed. Instead, bis(1,2-diisopropyl-1,2-diaza-3,5-diphenyl-3,5-diborolidinyl) (C-C) (6) formed. In contrast this, C-silylation heterocycle 7 effected salt trimethylsilyl chloride. Similarly, treatment HgCl2 molar equivalents gave rise formation bis(1,2-diisopropyl-1,2-diaza-3,5-diphenyl-3,5-diborolidinyl)mercury (8). novel compounds characterized elemental analyses and various spectroscopic methods (1H-, 11B{1H}-, 13C{1H} NMR, MS). molecular structures 6–8 elucidated X-ray diffraction analyses.