Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, AB, Canada T6G 2G2.
Dalton Trans. 2013 Apr 7;42(13):4625-32. doi: 10.1039/c3dt32988g.
The dehydrogenation of primary and secondary amine-boranes (RNH(2)·BH(3) and R(2)NH·BH(3); R = alkyl groups) was studied using the bulky N-heterocyclic carbene IPr (IPr = [(HCNDipp)C:]; Dipp = 2,6-(i)Pr(2)C(6)H(3)) as a stoichiometric dehydrogenation agent. In the case of primary amine-boranes, carbene-bound adducts IPr·BH(2)-NH(R)-BH(3) were obtained in place of the desired polymers RNH-BH(2). The secondary amine-borane (i)Pr(2)NH·BH(3) participated in dehydrogenation chemistry with IPr to afford the aminoborane [(i)Pr(2)N=BH(2)] and the dihydroaminal IPrH(2) as products. Attempts to induce H(2) elimination from the arylamine-borane DippNH(2)·BH(3) yielded a reaction mixture containing the known species IPr·BH(2)NHDipp, IPr·BH(2)NH(Dipp)-BH(3), free DippNH(2) and IPrH(2). The new hindered aryl-amine borane adduct ArNH(2)·BH(3) [Ar = 2,6-(Ph(2)CH)(2)-4-MeC(6)H(2)] underwent a reaction with IPr to give IPr·BH(3) and free ArNH(2), consistent with the presence of a weaker N-B dative bond in ArNH(2)·BH(3) relative to its less hindered amine-borane analogues.
一级和二级胺硼烷（RNH(2)·BH(3)和 R(2)NH·BH(3)；R = 烷基）的脱氢反应使用大位阻 N-杂环卡宾 IPr（IPr = [(HCNDipp)C：]；Dipp = 2,6-(i)Pr(2)C(6)H(3))作为化学计量的脱氢试剂进行研究。在一级胺硼烷的情况下，得到了碳宾键加合物 IPr·BH(2)-NH(R)-BH(3)，而不是所需的聚合物RNH-BH(2)。二级胺硼烷(i)Pr(2)NH·BH(3)与 IPr 参与脱氢化学反应，生成氨基硼烷[(i)Pr(2)N=BH(2)]和二氢氨化 IPrH(2)作为产物。试图从芳基胺硼烷 DippNH(2)·BH(3)中诱导 H(2)消除，得到的反应混合物含有已知的物种 IPr·BH(2)NHDipp、IPr·BH(2)NH(Dipp)-BH(3)、游离的 DippNH(2)和 IPrH(2)。新型受阻芳基胺硼烷加合物 ArNH(2)·BH(3) [Ar = 2,6-(Ph(2)CH)(2)-4-MeC(6)H(2)]与 IPr 反应生成 IPr·BH(3)和游离的 ArNH(2)，这与 ArNH(2)·BH(3)中较弱的 N-B 配位键的存在一致，相对于其无阻碍的胺硼烷类似物。
