Reversible Hydrogenation–Oxidative Dehydrogenation of Quinolines over a Highly Active Pt Nanowire Catalyst under Mild Conditions

Abstract

Over the wire and back again: The reversible hydrogenation–oxidative dehydrogenation of quinolines is reported by using Pt nanowire (NW) as the catalyst under mild reaction conditions. Pt NW shows high activity and selectivity in the hydrogenation of quinolines under H2 pressure (1 bar=100 kPa), and these hydrogenation products can be easily oxidized under the same conditions in an atmosphere of oxygen (1 bar) or in air.

Explaining the Size Dependence in Platinum‐Nanoparticle‐Catalyzed Hydrogenation Reactions

“…However, many synthetic PtNPs show low catalytic activity in hydrogenation of certain functionalities and undesired selectivity when dealing with multifunctional molecules . In the regioselective hydrogenation of quinoline with hydrogen, which is important for the synthesis of many biologically active molecules, both homo‐ and heterogeneous catalytic systems have been developed including transition‐metal complexes and nanoparticles . However, they usually require very harsh conditions, for example, a high hydrogen pressure (1–4 MPa) or an elevated temperature (40–200 °C), which may cause high cost and potential safety concerns in practical operations.…”

A Reusable Cobalt Catalyst for Reversible Acceptorless Dehydrogenation and Hydrogenation of N‐Heterocycles

“…Conventionally, dehydrogenation reactions were performed using the stoichiometric amount of strong oxidants such as DDQ, peroxides, iodates, chromium (IV) reagents and metal oxides, which often produce excess hazardous waste . An alternative to these toxic oxidants, pressurized air or oxygen was used as the sole oxidant . Catalytic dehydrogenation can also be performed in presence of hydrogen acceptors such as sterically hindered alkenes, and ketones .…”

Explaining the Size Dependence in Platinum‐Nanoparticle‐Catalyzed Hydrogenation Reactions

“…[15][16][17][18][19] In am ore specific scenario, supported Pt nanoparticles (PtNPs) are promising candidates for various hydrogenation reactions.H owever,m any synthetic PtNPs show low catalytic activity in hydrogenation of certain functionalities and undesired selectivity when dealing with multifunctional molecules. [20,21] In the regioselective hydrogenation of quinoline with hydrogen, which is important for the synthesis of many biologically active molecules, [22] both homo-and heterogeneous catalytic systems have been developed including transition-metal complexes [23][24][25][26] and nanoparticles. [20,21,27,28] However,t hey usually require very harsh conditions,f or example,ahigh hydrogen pressure or an elevated temperature (40-200 8 8C), which may cause high cost and potential safety concerns in practical operations.Although there have been few reports of catalysts that allow the regioselective hydrogenation of quinoline and its derivatives under relatively mild conditions, [23,28] it remains ac hallenge to fully manipulate the properties and performance of the catalysts to give optimal catalytic systems.…”