Intramolecular C-H Functionalization Followed by a [2σ+2π] Addition via an Intermediate Nickel-Nitridyl Complex
Intramolecular C-H Functionalization Followed by a [2σ+2π] Addition via an Intermediate Nickel-Nitridyl Complex
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DOI：
10.1021/acs.inorgchem.9b00168
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发表时间：
2019-06-03
影响因子：
4.6
通讯作者：
Lee, Wei-Tsung
中科院分区：
文献类型：
--
作者：
Ghannam, Jack;Sun, Zhicheng;Lee, Wei-Tsung
对双苯型Ni（II）叠氮配合物[Cz（tBu）（Pyr（iPr））（2）NiN 3]（1）的辐照显示出前所未有的镍配合物[Cz（tBu）（Pyr（iPr））（NH 2-Pyr（iPr））]（2），分离产率>90%。通过单晶X射线衍射分析，证明2是由一个推定的镍氮中间体[Cz（tBu）（Pyr（iPr））（2）Ni（sic）N-中心点]分子内C-H双重活化而产生的。计算支持在失去N-2后产生具有显着氮啶基自由基特征的中间体，该中间体反过来经历串联的C-H活化，从而产生官能化的中间体和产物。这是瞬时Ni（sic）N-中心点促进的分子内C-H官能化的前所未有的实例，随后是[2（sigma）+2（pi）]加成，产生双金属环产物2。从Ni（I）前体Cz（tBu）（Pyr（iPr））（2）Ni（3）和Me 3SiN 3的反应中也观察到了配合物2，这表明了通向掩蔽的镍-氮啶基中间体的独特的热途径。
Irradiation of a disphenoidal Ni(II) azido complex, [Cz(tBu)(Pyr(iPr))(2)NiN3] (1), revealed an unprecedented nickel complex, [Cz(tBu)(Pyr(iPr))(NH2-Pyr(iPr))] (2), in >90% isolated yield. As evidenced by single-crystal X-ray diffraction, 2 is produced by double intramolecular C-H activation of a putative nickel_nitridyl intermediate, [Cz(tBu)(Pyr(iPr))(2)Ni(sic)N-center dot]. Calculations support the generation of an intermediate with significant nitridyl radical character after the loss of N-2, which, in turn, undergoes tandem C-H activations, leading to functionalized intermediates and products. This is an unprecedented example of transient Ni(sic)N-center dot-promoted intramolecular C-H functionalization, followed by a [2(sigma) + 2(pi)] addition, yielding bis-metallacyclic product 2. Complex 2 is also observed from the reaction of Ni(I) precursor Cz(tBu)(Pyr(iPr))(2)Ni (3) and Me3SiN3, suggesting a unique thermal route toward a masked nickel-nitridyl intermediate.