Chia Cher-Chiek, Teo Yeow-Chuan, Cham Ning, Ho Samuel Ying-Fu, Ng Zhe-Hua, Toh Hui-Min, Mézailles Nicolas, So Cheuk-Wai
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.
Laboratoire Hétérochimie Fondamentale et Appliquée, CNRS, Université Paul Sabatier, 31062 Toulouse, France.
Inorg Chem. 2021 Apr 5;60(7):4569-4577. doi: 10.1021/acs.inorgchem.0c03507. Epub 2021 Mar 18.
This study describes the first use of a bis(phosphoranyl)methanido aluminum hydride, [ClC(PPhNMes)AlH] (, Mes = MeCH), for the catalytic hydroboration of CO. Complex was synthesized by the reaction of a lithium carbenoid [Li(Cl)C(PPhNMes)] with 2 equiv of AlH·NEtMe in toluene at -78 °C. (10 mol %) was able to catalyze the reduction of CO with HBpin in CD at 110 °C for 2 days to afford a mixture of methoxyborane [MeOBpin] (; yield: 78%, TOF: 0.16 h) and bis(boryl)oxide [pinBOBpin] (). When more potent [BH·SMe] was used instead of HBpin, the catalytic reaction was extremely pure, resulting in the formation of trimethyl borate [B(OMe)] () [catalytic loading: 1 mol % (10 mol %); reaction time: 60 min (5 min); yield: 97.6% (>99%); TOF: 292.8 h (356.4 h)] and BO (). Mechanistic studies show that the Al-H bond in complex activated CO to form [ClC(PPhNMes)Al(H){OC(O)H}] (), which was subsequently reacted with BH·SMe to form and , along with the regeneration of complex . Complex also shows good catalytic activity toward the hydroboration of carbonyl, nitrile, and alkyne derivatives.
本研究描述了首次使用双（磷酰基）甲烷铝氢化物[ClC(PPhNMes)AlH]（，Mes = MeCH）催化一氧化碳的硼氢化反应。配合物通过锂卡宾[Li(Cl)C(PPhNMes)]与2当量的AlH·NEtMe在甲苯中于-78°C反应合成。（10 mol%）能够在110°C下于CD中用HBpin催化一氧化碳的还原反应2天，得到甲氧基硼烷[MeOBpin]（；产率：78%，TOF：0.16 h⁻¹）和双（硼基）氧化物[pinBOBpin]（）的混合物。当使用更强效的[BH·SMe]代替HBpin时，催化反应极其纯净，生成硼酸三甲酯[B(OMe)₃]（；催化负载量：1 mol%（10 mol%）；反应时间：60分钟（5分钟）；产率：97.6%（>99%）；TOF：292.8 h⁻¹（356.4 h⁻¹））和BO（）。机理研究表明，配合物中的Al-H键活化一氧化碳形成[ClC(PPhNMes)Al(H){OC(O)H}]（），其随后与BH·SMe反应形成和，同时配合物再生。配合物对羰基、腈和炔烃衍生物的硼氢化反应也表现出良好的催化活性。
