NEW AIR-STABLE TRIMETHYLSILYL-SUBSTITUTED TRIVININYLBORANES AND CARBORANES

Article abstract of DOI:10.1016/0022-328X(85)87034-0

The reaction of B5H9 with (CH3)3SiC<*>CR (R=(CH3)3Si, CH3 or H) without the use of a Lewis base, heat, solvent, or large volume gas bulbs produced air-stable B and 2-(CH3)3Si-3-R-2,3-C2B4H6 in quantitative yields.However, this reaction was very solw.The reaction of BH3*THf with (CH3)3SiC<*>CR at 0 deg C also quantitatively produced the corresponding trivinylborane derivative, in which the boron is bonded exclusively to the silicon bearing olefinic carbon of each of the vinyl groups.The most satisfactory method of preparation of the carborane involved the liquid phase of a mixture of B5H9 and (CH3)3SiC<*>CR at 135 deg C with the formation of hydroborated species in a high vacuum stainless steel reactor.The carborane product was easily isolated in gram quantities in high purity by vacuum fractionation.All new products were characterized by IR, 1H, 11B, 13 C, and 29Si NMR spectroscopy, mass spectrometry, and, where possible, elemental analysis.