The Synthesis, Characterization and Dehydrogenation of Sigma-Complexes of BN-Cyclohexanes.
The Synthesis, Characterization and Dehydrogenation of Sigma-Complexes of BN-Cyclohexanes.
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BN-环己烷的 Sigma 配合物的合成、表征和脱氢。
DOI：
10.1002/chem.201502986
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发表时间：
2016-01-04
期刊：
影响因子：
--
通讯作者：
Weller AS
中科院分区：
文献类型：
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作者：
Kumar A;Ishibashi JS;Hooper TN;Mikulas TC;Dixon DA;Liu SY;Weller AS
研究了1，2-BN-环己烷2，2-R2 - 1，2-B，N-C_4 H_（10）（R2=HH，MeH，Me 2）与Ir和Rh金属碎片的配位化学。这导致[Ir（PCy 3）2（H）2（η2η2-H2 BNR 2C 4 H8）][BArF 4]（NR 2 = NH 2，NMeH）和[Rh（iPr 2 PCH 2CH 2CH 2 PiPr 2）（η2 η 2-H2 BNR 2C 4 H8）][BArF 4]（NR 2 = NH 2，NMeH，NMe 2）的溶液（NMR光谱）和固态（X射线衍射）表征。对于NR 2 = NH 2，随后的金属促进的脱氢偶联显示最终通过氨基硼烷形成环状三环硼氮烷[BNC 4 H8]3，并且使用DFT/GIAO化学位移计算初步表征为环硼氮烷中间体。对于NR 2 =NMeH，最终产物是环状氨基硼烷HBNMeC 4 H8。探讨了{Rh（iPr_2PCH_2CH_2CH_2PiPr_2）}~+催化2，2-H，Me-1，2-B，N-C_4 H_（10）脱氢反应的机理。催化实验表明，二聚体物种，[Rh 2（iPr 2 PCH 2CH 2CH 2 PiPr 2）2 H5][BArF 4]的快速形成。使用从该二聚体开始的初始速率方法，建立了与[胺硼烷]的一级关系，但与[Rh]的半级关系，这被认为是由于快速的二聚体-单体平衡操作。
The coordination chemistry of the 1,2‐BN‐cyclohexanes 2,2‐R2‐1,2‐B,N‐C4H10 (R2=HH, MeH, Me2) with Ir and Rh metal fragments has been studied. This led to the solution (NMR spectroscopy) and solid‐state (X‐ray diffraction) characterization of [Ir(PCy3)2(H)2(η2η2‐H2BNR2C4H8)][BArF 4] (NR2=NH2, NMeH) and [Rh(iPr2PCH2CH2CH2PiPr2)(η2η2‐H2BNR2C4H8)][BArF 4] (NR2=NH2, NMeH, NMe2). For NR2=NH2 subsequent metal‐promoted, dehydrocoupling shows the eventual formation of the cyclic tricyclic borazine [BNC4H8]3, via amino‐borane and, tentatively characterized using DFT/GIAO chemical shift calculations, cycloborazane intermediates. For NR2=NMeH the final product is the cyclic amino‐borane HBNMeC4H8. The mechanism of dehydrogenation of 2,2‐H,Me‐1,2‐B,N‐C4H10 using the {Rh(iPr2PCH2CH2CH2PiPr2)}+ catalyst has been probed. Catalytic experiments indicate the rapid formation of a dimeric species, [Rh2(iPr2PCH2CH2CH2PiPr2)2H5][BArF 4]. Using the initial rate method starting from this dimer, a first‐order relationship to [amine‐borane], but half‐order to [Rh] is established, which is suggested to be due to a rapid dimer–monomer equilibrium operating.