3420-02-8Relevant articles and documents
β-Amino alcohols from anilines and ethylene glycol through heterogeneous Borrowing Hydrogen reaction
Llabres-Campaner, Pedro J.,Ballesteros-Garrido, Rafael,Ballesteros, Rafael,Abarca, Belén
supporting information, p. 5552 - 5561 (2017/08/22)
Borrowing Hydrogen (BH), also called Hydrogen Autotransfer (HA), reaction with neat ethylene glycol represents a key step in the preparation of β-amino alcohols. However, due to the stability of ethylene glycol, mono-activation has rarely been achieved. Herein, a combination of Pd/C and ZnO is reported as heterogeneous catalyst for this BH/HA reaction. This system results in an extremely air and moisture stable, and economic catalyst able to mono-functionalize ethylene glycol in water, without further activation of the diol. In this work, different diols and aromatic amines have been explored affording a new approach towards amino alcohols. This study reveals how the combination of two solid species can afford interesting catalytic properties in heterogeneous phase. ZnO activates ethylene glycol while Pd/C is the responsible of the BH/HA cycle. This catalytic system has also been found useful to dehydrogenate indoles affording indolines that undergo in situ BH/HA cycle prior to re-aromatization, representing a tandem heterogeneous process.
Ruthenium-catalyzed heteroannulation of anilines with alkanolammonium chlorides leading to indoles
Cho, Chan Sik,Kim, Jin Hwang,Kim, Tae-Jeong,Shim, Sang Chul
, p. 3321 - 3329 (2007/10/03)
Anilines react with alkanolammonium chlorides in an aqueous medium (H2O-dioxane) at 180°C in the presence of a catalytic amount of a ruthenium catalyst together with SnCl2·2H2O to afford the corresponding indoles in moderate to good yields. Especially, when triisopropanolammonium chloride is employed to react with anilines, 2-methylindoles are formed regioselectively. The presence of SnCl2·2H2O is necessary for the effective formation of indoles. A reaction pathway involving alkanol group transfer from alkanolamines to anilines, N-alkylation of anilines by anilinoalkanols and heteroannulation of 1,2-dianilinoalkanes is proposed for this catalytic process.
Ruthenium-catalysed synthesis of indoles from anilines and trialkanolamines in the presence of tin(II) chloride dihydrate
Cho, Chan Sik,Lim, Hyo Kyun,Shim, Sang Chul,Kim, Tae Jeong,Choi, Heung-Jin
, p. 995 - 996 (2007/10/03)
Anilines react with trialkanolamines in dioxane in the presence of a catalytic amount of a ruthenium catalyst together with tin(II) chloride dihydrate to give the corresponding indoles in moderate to good yields.