Rhenium-Catalyzed [4 + 1] Annulation of Azobenzenes and Aldehydes via Isolable Cyclic Rhenium(I) Complexes
作者:Xiaoyu Geng、Congyang Wang
DOI:10.1021/acs.orglett.5b00938
日期:2015.5.15
The first Re-catalyzed [4 + 1] annulation of azobenzenes with aldehydes was developed to furnish 2H-indazoles via isolable and characterized cyclic ReI-complexes. For the first time, the acetate-acceleration effect is showcased in Re-catalyzed C–H activation reactions. Remarkably, mechanistic studies revealed an irreversible aldehyde-insertion step, which is in sharp contrast to those of previous Rh-
Structure−Reactivity Correlation of Anilines in Acetic Acid
作者:Chockalingam Karunakaran、Ramasamy Kamalam
DOI:10.1021/jo0158433
日期:2002.2.1
The oxidation of aniline in glacial acetic acid with percarbonate, a dry carrier of hydrogen peroxide, is a second-order reaction conforming to the isokinetic relationship. The hitherto followed method of correlation of the reaction rates in terms of the structure-reactivity relationships is unsatisfactory and erroneous. But the reaction rates of molecular anilines, obtained for the first time, conform
Lead-Catalyzed Synthesis of Azo Compounds by Ammonium Acetate Reduction of Aromatic Nitro Compounds
作者:G. R. Srinivasa、K. Abiraj、D. Channe Gowda
DOI:10.1081/scc-120026850
日期:2003.12.31
Lead/ammonium acetate is a convenient reagent for the reduction of aromaticnitrocompounds to the corresponding symmetrically substituted azo compounds. Various azo compounds containing additional reducible substituents such as halogen, nitrile, acid, phenol, ester, methoxy, etc., functions have been synthesized in a single step by the use of this reagent. The conversion is reasonably fast, clean,
Rhenium-catalyzed C–H aminocarbonylation of azobenzenes with isocyanates
作者:Xiaoyu Geng、Congyang Wang
DOI:10.1039/c5ob01121c
日期:——
The first C–H aminocarbonylation of azobenzenes with isocyanates is achieved by using rhenium-catalysis, which provides an atom-economical access to o-azobenzamides.
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。