Mechanistic Insights on Reduction of Carboxamides by Diisobutylaluminum Hydride and Sodium Hydride-Iodide Composite
Mechanistic Insights on Reduction of Carboxamides by Diisobutylaluminum Hydride and Sodium Hydride-Iodide Composite
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二异丁基氢化铝和氢化碘化钠复合物还原甲酰胺的机理见解
DOI：
10.1002/hlca.201900166
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发表时间：
2019
影响因子：
1.8
通讯作者：
Chiba Shunsuke
中科院分区：
文献类型：
--
作者：
Ong Derek Yiren;Watanabe Kohei;Takita Ryo;Chiba Shunsuke
通过计算和实验方法，阐明了二异丁基氢化铝（DIBAL）和氢化钠（NaH）-碘化钠（NaI）复合物还原叔酰胺的反应机理.用DIBAL还原N，N-二甲基甲酰胺可得到相应的胺，而用NaH-NaI复合物还原N，N-二甲基甲酰胺则只生成醛，即使在高反应温度下也是如此。DFT计算表明，DIBAL的二聚体结构和Al中心上的Lewis酸性是通过C−O键断裂分解四面体阴离子甲醇胺中间体的关键.另一方面，在用NaH-NaI复合物还原时，所得四面体阴离子甲醇胺中间体可以保持稳定，从而通过水处理提供醛作为唯一产物
The reaction mechanisms on reduction of tertiary carboxamides by diisobutylaluminum hydride (DIBAL) and sodium hydride (NaH)‐sodium iodide (NaI) composite were elucidated by the computational and experimental approaches. Reduction ofN,N‐dimethyl carboxamides with DIBAL provides the corresponding amines, whereas that with the NaH−NaI composite exclusively forms aldehyde even at high reaction temperature. DFT calculations revealed that dimeric structural nature of DIBAL andLewisacidity on its Al center play crucial role to decompose the tetrahedral anionic carbinol amine intermediate through C−O bond cleavage. On the other hand, in the reduction with the NaH−NaI composite, the resulting tetrahedral anionic carbinol amine intermediate could be kept stable, thus providing aldehydes as a sole product by the aqueous workup