An Electron-Poor Dioxa-[2.1.1]-(2,6)-pyridinophane Ligand and Its Application in Cu-Catalyzed Olefin Aziridination
An Electron-Poor Dioxa-[2.1.1]-(2,6)-pyridinophane Ligand and Its Application in Cu-Catalyzed Olefin Aziridination
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一种贫电子二氧杂-[2.1.1]-(2,6)-吡啶芬配体及其在铜催化烯烃氮丙啶化反应中的应用
DOI：
10.1021/acs.inorgchem.9b02618
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发表时间：
2019
影响因子：
4.6
通讯作者：
Vedernikov, Andrei N.
中科院分区：
文献类型：
--
作者：
Yang, Fan;Ruan, Jiaheng;Zavalij, Peter Y.;Vedernikov, Andrei N.
合成了一个新的大环1，7-二氧杂-[2.1.1]-（2，6）-吡啶并吡喃配体，并对其进行了晶体学表征。制备了二氯钯（II）和氯铜（I）两种衍生的金属配合物。在钯（II）配合物LPdCl 2中，无论是在固态，根据其晶体学表征，还是在−40 °C的CH 2Cl 2溶液中，根据1H NMR光谱，配体都采用C1-对称κ2-N，N-配位模式，其中金属原子与大环的两个不等价的吡啶片段结合。该配合物在20 °C时是流动的。在结晶铜（I）络合物LCuCl中，大环配体也与金属κ2-N，N-配位，但它利用两个等价的吡啶片段进行结合。铜（I）配合物在20至−70 °C的温度范围内在CH 2Cl 2溶液中是流动的，并且被认为参与了快速的分子间大环配体交换，该交换在−40 °C以下减慢。密度泛函理论计算预测了二氧杂吡啶并吡喃衍生的配合物LPdCl 2和LCuCl的热力学稳定性较低，与它们的[2.1.1]-（2，6）-吡啶并吡喃类似物相比，其含有桥接CH 2基团而不是氧原子。贫电子的二氧杂吡啶并吩氯铜（I）配合物与NaBArF 4（BArF 4 =四[3，5-双（三氟甲基）苯基]硼酸盐）在二氯甲烷溶液中组合，可以用作在0-22 ℃下用PhINT对各种烯烃进行氮丙啶化的有效催化剂。
A novel macrocyclic 1,7-dioxa-[2.1.1]-(2,6)-pyridinophane ligand has been synthesized and crystallographically characterized. Two derived metal complexes, dichloropalladium(II) and chlorocopper(I), were prepared. In the palladium(II) complex LPdCl2, both in the solid state, according to its crystallographic characterization, and in CH2Cl2solutions at −40 °C, according to1H NMR spectroscopy, the ligand adapts aC1-symmetric κ2-N,N-coordination mode in which the metal atom binds to two nonequivalent pyridine fragments of the macrocycle. The complex is fluxional at 20 °C. In the crystalline copper(I) complex LCuCl, the macrocyclic ligand is also κ2-N,N-coordinated to the metal, but it utilizes two equivalent pyridine fragments for the binding. The copper(I) complex is fluxional in CH2Cl2solutions in the temperature range between 20 and −70 °C and is proposed to be involved in a fast intermolecular macrocyclic ligand exchange which is slowed down below −40 °C. DFT calculations predict a lower thermodynamic stability of the dioxapyridinophane-derived complexes LPdCl2and LCuCl, as compared to their [2.1.1]-(2,6)-pyridinophane analogs containing bridging CH2groups instead of the oxygen atoms. The electron poor dioxapyridinophane chlorocopper(I) complex, in combination with NaBArF4(BArF4= tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) in dichloromethane solutions, can serve as an efficient catalyst for aziridination of various olefins with PhINTs at 0–22 °C.