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RESEARCH PRODUCT

β-Amino alcohols from anilines and ethylene glycol through heterogeneous Borrowing Hydrogen reaction

Rafael Ballesteros-garridoBelén AbarcaRafael BallesterosPedro J. Llabres-campaner

subject

TandemHydrogen010405 organic chemistryChemistryOrganic ChemistryDiolBorrowing hydrogenchemistry.chemical_element010402 general chemistryHeterogeneous catalysis01 natural sciencesBiochemistry0104 chemical sciencesCatalysischemistry.chemical_compoundPhase (matter)Drug DiscoveryOrganic chemistryEthylene glycol

description

Abstract 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.

https://doi.org/10.1016/j.tet.2017.08.006