Carbon−Nitrogen Bond Formation Involving Well-Defined Aryl−Copper(III) Complexes
摘要:
Carbon-heteroatom bond formation from copper(III) is commonly invoked as a key step in catalytic reactions, including the century-old Ullmann reactions. Well-defined examples of such reactions have never been observed. Here, we demonstrate that a well-defined Cu(III)-aryl species reacts with a variety nitrogen nucleophiles to undergo facile carbon-nitrogen bond formation.
Oxidant-Free Au(I)-Catalyzed Halide Exchange and C<sub>sp2</sub>–O Bond Forming Reactions
作者:Jordi Serra、Christopher J. Whiteoak、Ferran Acuña-Parés、Marc Font、Josep M. Luis、Julio Lloret-Fillol、Xavi Ribas
DOI:10.1021/jacs.5b08756
日期:2015.10.21
character, Au(I)/Au(III) redox properties or a combination of both. As a result of the high oxidation potential of the Au(I)/Au(III) couple, redox catalysis involving Au typically requires the use of a strong external oxidant. This study demonstrates unusual external oxidant-free Au(I)-catalyzedhalide exchange (including fluorination) and Csp2-O bond formation reactions utilizing a model arylhalide macrocyclic
Au 已被证明通过利用其 π 路易斯酸特性、Au(I)/Au(III) 氧化还原特性或两者的组合来介导许多有机转化。由于 Au(I)/Au(III) 对的高氧化电位,涉及 Au 的氧化还原催化通常需要使用强外部氧化剂。该研究展示了不寻常的无外部氧化剂 Au(I) 催化的卤化物交换(包括氟化)和使用模型芳基卤化物大环底物的 Csp2-O 键形成反应。此外,卤化物交换和 Csp2-O 偶联反应性也可以外推到带有单个螯合基团的底物,从而进一步了解反应机制。这项工作提供了无外部氧化剂的 Au(I) 催化碳-杂原子交叉偶联反应的第一个例子。
Trifluoromethylation of a Well-Defined Square-Planar Aryl-Ni<sup>II</sup>
Complex involving Ni<sup>III</sup>
/CF<sub>3</sub>
<sup>.</sup>
and Ni<sup>IV</sup>
−CF<sub>3</sub>
Intermediate Species
作者:Mireia Rovira、Steven Roldán-Gómez、Vlad Martin-Diaconescu、Christopher J. Whiteoak、Anna Company、Josep M. Luis、Xavi Ribas
DOI:10.1002/chem.201702168
日期:2017.8.25
Ni‐mediated trifluoromethylation of an aryl−Br bond in model macrocyclic ligands (Ln−Br) has been thoroughly studied, starting with an oxidative addition at Ni0 to obtain well‐defined aryl‐NiII‐Br complexes ([Ln−NiII]Br). Abstraction of the halide with AgX (X=OTf− or ClO4−) thereafter provides [Ln−NiII](OTf). The nitrate analogue has been obtained through a direct C−H activation of an aryl−H bond using NiII
镍-介导的芳基- Br键的三氟甲基化在模型的大环配体(L Ñ -Br)已被彻底研究,开始用氧化加成在镍0,以获得良好定义的芳基-镍II -Br络合物([L Ñ - Ni II ] Br)。与卤化银的卤化物的抽象(X =光学传递函数-或C10 4 - )之后提供[L Ñ -Ni II ](OTF)。硝酸盐类似物是通过使用Ni II直接对芳基-H键进行CH-H活化而获得的盐,这条路线已经通过X射线吸收光谱法(XAS)进行了研究。晶体学XRD和XAS表征表明,芳基-Ni II复合物中紧密的大环配位,这可能会阻碍与亲核试剂的直接反应。相反,观察到氧化剂具有增强的反应性,并且[L n -Ni II ](OTf)与CF 3 +源的反应提供了L n -CF 3。产品的定量产量。实验和理论机制相结合的研究为这种转变的运作机制提供了新的见解。计算分析表明,发生了初始单电子转移(SET)到5-(三氟甲基)二苯
The present invention relates to arene connected polyamine macrocyclic derivatives represented by general formula I, pharmaceutically acceptable salts or hydrates thereof which have anti-HIV activities, in which the definitions of substituents are as defined in the description; to preparation methods of the compounds of formula I; to pharmaceutical compositions containing the compounds of formula I or their pharmaceutically acceptable salts or hydrates; to the use of the compounds of formula I or their pharmaceutically acceptable salts or hydrates for the preparation of a medicament for the treatment and prevention of HIV-associated diseases.
Copper-catalyzed halide exchange reactions under very mild reaction conditions are described for the first time using a family of model aryl halide substrates. All combinations of halide exchange (I, Br, Cl, F) are observed using catalytic amounts of Cu-I. Strikingly, quantitative fluorination of aryl X substrates is also achieved catalytically at room temperature, using common F- sources, via the intermediacy of aryl-Cu-III-X species. Experimental and computational data support a redox Cu-I/Cu-III catalytic cycle involving aryl X oxidative addition at the Cu-I center, followed by halide exchange and reductive elimination steps. Additionally, defluorination of the aryl-F model system can be also achieved with Cu-I at room temperature operating under a Cu-I/Cu-III redox pair.