描述了几种类型的p -FC 6 H 4 ·Z·C 6 H 4 X类型的双核芳族化合物的合成[省略图示]。在19个˚Fnmrspectra被用于检查的取代基影响的传输,由于基团X,过桥Z.有必要“传输”(在区分反偶氮-和氧化偶氮基系列),其中电子密度可能是从一个环转移到另一个环并“中继”(顺-偶氮和-偶氮系列,以及偶氮系列),其中取代作用最可能是通过修饰相互连接的氮原子上非键合孤对之间的排斥相互作用而发生的。通过观察“透射”系列的4,4'-二氟成员的核磁共振谱中的氟核之间的长距离(11键)偶联,以及在其相应成员的谱中不存在氟核之间的长距离(11键)偶联,为这一建议提供了支持。 “继电器”系列。讨论了对最近的一些类似系列的长距离取代基效应的研究,并对结果进行了重新评估。在某些4-取代的苯乙烯衍生物中,对13 C和1 H nmr屏蔽数据进行了类似的处理。
A novel strategy for the dehydrogenation of the NH−NH bond is disclosed using potassium tert‐butoxide (tBuOK) in liquid ammonia (NH3) under air at room temperature. Its synthetic value is well demonstrated by the highly efficient synthesis of aromatic azo compounds (up to 100 % yield, 3 min), heterocyclic azo compounds, and dehydrazination of phenylhydrazine. The broad application of this strategy
Palladium-Catalyzed Oxidative Synthesis of Unsymmetrical Azophenols
作者:Thi Hong Long Nguyen、Nicolas Gigant、Sandrine Delarue-Cochin、Delphine Joseph
DOI:10.1021/acs.joc.5b02614
日期:2016.3.4
reported. The developed methodology tolerates various functional groups and allows the synthesis of diverse unsymmetrical azophenols under mild conditions in good to excellent yields. A complementary procedure was also investigated by in situ generation of PIFA. This study represents the first general method for the synthesis of o-hydroxyazobenzenes starting from simple azoarenes.
molybdenum oxide compound, [N(C4H9)4]2[Mo6O19] (1), catalyzed selective oxidation of anilines with hydrogen peroxide as green oxidant. The oxidation of anilines can be realized in a fully selectively fashion to afford various symmetric/asymmetric azobenzene and azoxybenzene compounds, respectively, by changing additive and solvent, avoiding the use of stoichiometric metal oxidants. Preliminary mechanistic
在医药和工业应用中起重要作用的芳族偶氮化合物在合成中仍然面临巨大挑战。在此,我们报道了一种氧化钼化合物[N(C 4 H 9)4 ] 2 [Mo 6 O 19 ](1),用过氧化氢作为绿色氧化剂催化苯胺的选择性氧化。苯胺的氧化可以完全选择性地实现,通过改变添加剂和溶剂避免使用化学计量的金属氧化剂,从而分别提供各种对称/不对称的偶氮苯和and氧基苯化合物。初步的机理研究表明,高活性的反应性和难以捉摸的钼亚胺配合物是中间的。
Electrochemical dehydrogenation of hydrazines to azo compounds
作者:Ke-Si Du、Jing-Mei Huang
DOI:10.1039/c9gc00515c
日期:——
A strategy for the electrochemical dehydrogenation of hydrazine compounds is disclosed under ambient conditions. This protocol proceeded smoothly in ethanol by employing electrons as clean oxidants. Its synthetic value is well demonstrated by the highly efficient synthesis of symmetric and unsymmetric azo compounds. It is an environmentally friendly transformation and the present protocol was effective