Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany.
Dalton Trans. 2018 Jun 25;47(25):8402-8417. doi: 10.1039/c8dt01836g.
Hydroalumination of R-P(H)-C[triple bond, length as m-dash]C-tBu with bulky H-Al[CH(SiMe3)2]2 afforded the new P-H functionalized Al/P-based frustrated Lewis pair R-P(H)-C[[double bond, length as m-dash]C(H)-tBu]-AlR2 [R = CH(SiMe3)2; FLP 7]. A weak adduct of 7 with benzonitrile (8) was detected by NMR spectroscopy, but could not be isolated. tert-Butyl isocyanide afforded a similar, but isolable adduct (9), in which the isocyanide C atom was coordinated to aluminium. The unique reactivity of 7 became evident from its reactions with the heteroatom substituted nitriles PhO-C[triple bond, length as m-dash]N, PhCH2S-C[triple bond, length as m-dash]N and H8C4N-C[triple bond, length as m-dash]N. Hydrophosphination of the C[triple bond, length as m-dash]N triple bonds afforded imines at room temperature which were coordinated to the FLP by Al-N and P-C bonds to yield AlCPCN heterocycles (10 to 12). These processes depend on substrate activation by the FLP. Diphenylcyclopropenone and its sulphur derivative reacted with 7 by addition of the P-H bond to a C-C bond of the strained C3 ring and ring opening to afford the fragment (Z)-Ph-C(H)[double bond, length as m-dash]C(Ph)-C-X-Al (X = O, S). The C-O or C-S groups were coordinated to the FLP to yield AlCPCX heterocycles (13 and 14). The thiocarbonyl derived compound 14 contains an internally stabilized phosphenium cation with a localized P[double bond, length as m-dash]C bond, a trigonal planar coordinated P atom and a short P[double bond, length as m-dash]C distance (168.9 pm). Insight into formation mechanisms, the structural and energetic properties of FLP 7 and compounds 13 and 14 was gained by quantum chemical DFT calculations.
与大位阻的 H-Al[CH(SiMe3)2]2 反应，R-P(H)-C[三键, 长度 as m-dash]C-tBu 发生氢铝化反应，得到新的 P-H 官能化的 Al/P 受阻路易斯对 R-P(H)-C[[双键, 长度 as m-dash]C(H)-tBu]-AlR2 [R = CH(SiMe3)2; FLP 7]。通过 NMR 光谱检测到 7 与苯甲腈（8）的弱加合物，但无法分离。叔丁基异氰化物得到类似但可分离的加合物（9），其中异氰化物 C 原子与铝配位。7 的独特反应性从其与取代的腈 PhO-C[三键, 长度 as m-dash]N、PhCH2S-C[三键, 长度 as m-dash]N 和 H8C4N-C[三键, 长度 as m-dash]N 的反应中表现出来。C[三键, 长度 as m-dash]N 三键的膦氢化反应在室温下生成亚胺，它们通过 Al-N 和 P-C 键与 FLP 配位，生成 AlCPCN 杂环（10 至 12）。这些过程取决于 FLP 对底物的活化。二苯基环丙烯酮及其硫代衍生物通过 P-H 键加成到应变 C3 环的 C-C 键并开环，与 7 反应，得到片段（Z）-Ph-C(H)[双键, 长度 as m-dash]C(Ph)-C-X-Al（X = O、S）。C-O 或 C-S 基团与 FLP 配位，生成 AlCPCX 杂环（13 和 14）。硫代羰基衍生化合物 14 含有一个内部稳定的磷翁阳离子，具有局部化的 P[双键, 长度 as m-dash]C 键、一个三角平面配位的 P 原子和一个短的 P[双键, 长度 as m-dash]C 距离（168.9 pm）。通过量子化学 DFT 计算，深入了解了 FLP 7 和化合物 13 和 14 的形成机制、结构和能量性质。
