Oxidation of aromatic amines with chromyl chloride-I
作者:C. Nallaiah、J.A. Strickson
DOI:10.1016/s0040-4020(01)87565-7
日期:1986.1
The oxidation of aromaticprimaryamines with chromyl chloride in carbon tetrachloride or chloroform, results in the formation of intermediate solid adducts (Etard adducts) which, on hydrolysis, give azobenzenes(1), 1,4-benzoquinones(2),anilino-1,4-benzoquinones(3), 1,4-benzoquinone anils(4)and anilino-1,4-benzoquinone anils (5) in yields which depend on the position, nature and degree of substitution
Synthetic and Mechanistic Studies of the Four-Electron Reduction of Dioxygen, NN, and NO Double Bonds by Tungsten(II) Aryloxide Compounds
作者:Margaret R. Lentz、Jonathan S. Vilardo、Mark A. Lockwood、Phillip E. Fanwick、Ian P. Rothwell
DOI:10.1021/om030604m
日期:2004.2.1
found to ring-open the substrates pyridazine, benzo[c]cinnoline, and phthalazine to produce the three new seven-membered diaza metallacycles 12−14. Structural studies show 12 and 14 to contain planar rings, whereas the two backbone phenyl rings in 13 are twisted by 33° with respect to each other. Structural parameters are more consistent with a formulation as a d0-W(VI) metal center with a 2,7-diazatungstahepta-1
I<sub>2</sub>-Mediated 2H-indazole synthesis via halogen-bond-assisted benzyl C–H functionalization
作者:Xiangli Yi、Lei Jiao、Chanjuan Xi
DOI:10.1039/c6ob01827k
日期:——
I2-Mediated benzyl C–H functionalization has been developed for the synthesis of 2H-indazoles, which features high efficiency, simple conditions and no need for metals. Mechanistic experiments and DFT calculations have revealed halogen bond assistance and a radical chain process for this reaction. The azo group and the bound iodine cooperate in the hydrogen abstraction step, which circumvents the thermodynamic
Transfer Hydrogenation of Azo Compounds with Ammonia Borane Using a Simple Acyclic Phosphite Precatalyst
作者:Miguel A. Chacón‐Terán、Rafael E. Rodríguez‐Lugo、Robert Wolf、Vanessa R. Landaeta
DOI:10.1002/ejic.201900572
日期:2019.10.31
Tris(quinolin‐8‐yl)phosphite, P(Oquin)3, promotes the dehydrogenation of H3N·BH3 (AB) and the transfer hydrogenation of azoarenes using ammonia borane (AB) as H2 source. The metal‐free reduction of azoarenes proceeds under mild reaction conditions upon which several diphenylhydrazine derivatives are obtained in high yields. The reactivity of P(Oquin)3 toward AB was evaluated through NMR in situ tests
三(喹啉-8-基)亚磷酸酯,P(Oquin)3,促进 H3N·BH3 (AB) 的脱氢和使用氨硼烷 (AB) 作为 H2 源的偶氮芳烃的转移氢化。偶氮芳烃的无金属还原在温和的反应条件下进行,在此条件下可以高产率地获得几种二苯肼衍生物。P(Oquin)3 对 AB 的反应性通过 NMR 原位测试进行评估。研究了反应速率、活化参数、氘动力学同位素效应(DKIE)和线性自由能关系。这种机械和动力学研究表明 P(Oquin)3 是一种前催化剂,并且 AB 可能参与反应途径的一个以上阶段。此外,动力学数据表明反应通过有序的过渡态进行,可能是缔合的。
N-alkylation andN-arylation of anilines starting from a mild N?Mg reagent: Its activation causing the ?N?C? coupling to extend the unified structure-reactivity relationship
New N-alkylation and N-arylation procedures starting from anilinomagnesium (ArNHMgBr) are reported. For N-alkylation with alkyl bromides, addition of hexamethylphosphoramide to an ArNHMgBr solution in tetrahydrofuran (THF) is effective. After heating at 55°C, N-monoalkylation product was obtained in 60–90% yield, slight dialkylation taking place. The combined use of aryliminodimagnesium [ArN(MgBr)2]