Reactions of Amine– and Phosphane–Borane Adducts with Frustrated Lewis Pair Combinations of Group 14 Triflates and Sterically Hindered Nitrogen Bases
作者:George R. Whittell、Edward I. Balmond、Alasdair P. M. Robertson、Sanjib K. Patra、Mairi F. Haddow、Ian Manners
DOI:10.1002/ejic.201000515
日期:2010.9
amine- and phosphane―borane adducts has been investigated. By using multinuclear NMR spectroscopy, it has been shown that Me 2 NH·BH 3 (11) is efficiently converted to [Me 2 N―BH 2 ] 2 (12) by the so-called "frustrated Lewis pair" (FLP) of nBu 3 SnOTf (4, ― OTf = ― OSO 2 CF 3 ) and 2,2,6,6-tetramethylpiperidine (6). Within the scope of the study, exchange of the Lewis acid effects the rate of dehydrogenation
已经研究了三烷基 14 三氟甲磺酸酯与胺和吡啶碱结合使胺 - 和磷烷 - 硼烷加合物脱氢的能力。通过使用多核 NMR 光谱,已表明 Me 2 NH·BH 3 (11) 通过所谓的“受挫路易斯对” (FLP) 有效地转化为 [Me 2 N-BH 2 ] 2 (12) nBu 3 SnOTf (4, ― OTf = ― OSO 2 CF 3 ) 和 2,2,6,6-四甲基哌啶 (6)。在研究范围内,路易斯酸的交换按顺序影响脱氢速率:4 > Me 3 Si-OTf (2) > Et 3 SiOTf (3)。路易斯碱与 2,6-二叔丁基吡啶 (5) 的交换也显示出降低反应速率,而 1,3-二叔丁基咪唑-2-亚基 (7) 直接与 2得到 1,3-双-叔丁基-4-(三甲基甲硅烷基)咪唑鎓三氟甲磺酸盐 (8[OTf])。对于脱氢反应时间较长的 FLP 组合,观察到可检测量的 [H 2 B(μ-H)(μ-NMe