Convenient reduction of azobenzenes and azoxybenzenes to hydrazobenzenes by sodium dithionite using dioctylviologen as an electron transfer catalyst
作者:Kwanghee Koh Park、Sun Young Han
DOI:10.1016/s0040-4039(96)01451-7
日期:1996.9
Various azobenzenes and azoxybenzenes were reduced almost quantitatively to the corresponding hydrazobenzenes by sodiumdithionite under mild conditions without the formation of aniline derivatives, using dioctyl viologen as an electron-transfer catalyst in acetonitrile-water.
Hydrated zirconia has been found to be an efficient and reusable catalyst for the regiospecificacylations for of arenes and selective reductions of azobenzenes to produce benzo-phenones and hydrazobenzenes respectively.
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。
Reformed polysilazane and method of producing same
申请人:TOA NENRYO KOGYO KABUSHIKI KAISHA
公开号:EP0304239A1
公开(公告)日:1989-02-22
A novel, reformed polysilazane obtained by reacting a polysilazane with a compound selected from ammonia, primary and secondary amines, hydrazine and mono-, di- and tri-substituted hydrazines to cross-link the polysilazane with the compound serving as a cross-linking agent or to link the compound to the polysilazane.