沮丧的路易斯对的化学结构源自N-杂环卡宾并且已经探究了许多路易斯酸。的结合1,3-双[2,6-(二-异-丙基)苯基] -1,3-咪唑-2-亚基(IDipp)(1)与B(C 6 F 5)3被证明可以产生经典的路易斯酸碱加合物(IDipp)B(C 6 F 5)3(2)。相比之下,组合1,3-二叔丁基-1,3-咪唑-2-亚烷基(3)与B(C 6 F 5)3证明形成了受挫的路易斯对,并与H 2反应以高收率得到盐[I t BuH] [HB(C 6 F 5)3 ](4) 。以类似的方式,将(3)添加到一系列胺中硼烷包括H 3 NB(C 6 F 5)3(5),PhH 2 NB(C 6 F 5)3(6)和PhH 2 NB(C 6 F 5)3(7)的加合物导致去质子化和形成氨基硼酸咪唑鎓盐[I t BuH] [H 2 NB(C 6 F 5)3 ](8),[I t BuH] [PhHNB(C 6 F 5)3 ](9)和[I
Synthesis, Structure, and Stability of Adducts between Phosphide and Amide Anions and the Lewis Acids Borane, Tris(pentafluorophenyl)borane, and Tris(pentafluorophenyl)alane
作者:Anna-Marie Fuller、Andrew J. Mountford、Matthew L. Scott、Simon J. Coles、Peter N. Horton、David L. Hughes、Michael B. Hursthouse、Simon J. Lancaster
DOI:10.1021/ic901799q
日期:2009.12.7
The phosphinoborane adduct H3P center dot B(C6F5)(3) can be deprotonated using LiN(SiMe3)(2) to give the phosphidoborate salt Li[H2PB(C6F5)(3)], which was converted to the phosphidodiborates Li[H2PB(C6F5)(3)}(2)] and Li[H2PB(C6F5)(3)}BH3}] by treatment with an equivalent of B(C6F5)(3) or Me2S center dot BH3, respectively. A series of anions of the form [RR'PM(C6F5)(3)}BH3}](-), where R = R' = Ph or R= Bu-t, R' = H, and M = B or Al, were prepared (through treatment of salts Li[RR'P(BH3)] with the corresponding Lewis acid) and characterized using multinuclear NMR elemental analysis and X-ray crystallography. The solid state structures of [Li(Et2O)(x)][Ph2PM(C6F5)(3)}BH3}] exhibit eta(2)-bonding of the BH3 group to the cationic lithium center. The attempted preparation of an analogous series with amide cores of the form [R2NB(C6F5)(3)}BH3}](-) proved unsuccessful; among the competing reaction pathways hydride abstraction occurred preferentially to yield Li[HB(C6F5)(3)] and dimers or higher oligorners with the composition (R2NBH2)(n).
Hydrogen and Amine Activation by a Frustrated Lewis Pair of a Bulky N‐Heterocyclic Carbene and B(C
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