direct oxidation of hydrazine HN–NH bonds to azo group functionality catalyzed by molecular iodine is disclosed. The strengths of this reactivity include rapid reaction times, low catalyst loadings, use of ambient dioxygen as a stoichiometric oxidant, and ease of experimental set-up and azo product isolation. Mechanistic studies and density functional theory computations offering insight into this reactivity
Accessing relatively electron poor cerium(<scp>iv</scp>) hydrazido complexes by lithium cation promoted ligand reduction
作者:Jessica R. Levin、Thibault Cheisson、Patrick J. Carroll、Eric J. Schelter
DOI:10.1039/c6dt03154d
日期:——
Ce(IV) product depended on the substituents on the N,N′-diarylhydrazido ligands. Isolable cerium products formed only with electron withdrawing substituents on the N,N′-diarylhydrazido rings, whereas electron donating substituents resulted in intractable mixtures of Ce(III) products and N,N′-bis(aryl)diazenes (ArNNAr). The presence of electron withdrawing substituents at the N,N′-diarylhydrazido ligands
一系列取代的N,N′-二芳基肼(ArNHNHAr),Ar = 3,5-(CH 3)-C 6 H 3; n =1。-Ph; 4-氯-C 6 H 4;3,5-Cl-C 6 H 3;3,5-(CF 3)-C 6 H 3与Ce(III)[N(SiMe 3)2 ] 3和锂化碱反应,探索使用Ce(III)作为还原剂并评估其影响配合物在所得配合物的铈金属中心电子结构上的取代度。该ñ,在所有情况下,N′-二芳基肼基配体均通过Li +阳离子配位,然后通过Ce(III)阳离子还原以形成Li 4(Et 2 O)4 [Ce IV(ArNNAr)4 ]配合物。所得Ce(IV)产物的稳定性取决于N,N′-二芳基肼基配体上的取代基。可分离的铈产物仅在N,N'-二芳基肼基环上具有吸电子取代基形成,而给电子取代基导致Ce(III)产物和N的难以混合的混合物,N′-双(芳基)二氮烯(ArN NAr)。在N,N'-二芳基肼基配
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。
Pyridazinedione derivatives, their preparation and pharmaceutical applications
申请人:ZENECA LIMITED
公开号:EP0512817A1
公开(公告)日:1992-11-11
The present invention relates to pyridazino[4,5-b]indoles,
and pharmaceutically useful salts thereof, which are excitatory amino acid antagonists and which are useful when such antagonism is desired such as in the treatment of neurological disorders. The invention further provides pharmaceutical compositions containing pyridazino[4,5-b]indoles as active ingredient, and methods for the treatment of neurological disorders.