Pd(II)−Hydrotalcite-Catalyzed Oxidation of Alcohols to Aldehydes and Ketones Using Atmospheric Pressure of Air

Abstract

A heterogenized Pd catalyst, Pd(II)-hydrotalcite (palladium(II) acetate-pyridine complex supported by hydrotalcite) catalyzes the aerobic oxidation in toluene of a variety of primary and secondary alcohols into the corresponding aldehydes and ketones in high yields using atmospheric pressure of air as a sole oxidant under mild conditions. This catalyst is also effective for the oxidation of allylic alcohols, especially such as geraniol and nerol, without any isomerization of an alkenic part. The catalyst can be easily prepared from all commercially available reagents and reused several times.

Pt@MOF‐177: Synthesis, Room‐Temperature Hydrogen Storage and Oxidation Catalysis

“…[70][71][72][73][74][75] The selective oxidation of alcohols yielding aldehydes and ketones is a highly important reaction and the developments of recent years tend to "green" chemistry reactions employing dioxygen or even air as an oxidant accompanied by mild reaction conditions (solvent-free, base-free). Most of the oxidation reactions are carried out at elevated temperatures between 80 8C [76,77,78] and 160 8C. [70] Room-temperature systems are quite rare.…”

Oxidation of Alcohols with Molecular Oxygen

“…The complex, heterogenized by stirring its toluenic solution with hydrotalcite, transformed benzyl alcohol in quantitative yield to benzaldehyde and allylic alcohols to aldehydes without isomerization [200]. A major drawback of this catalyst system was that the addition of at least four equivalents of pyridine to the reaction mixture was necessary to avoid reduction of Pd 2+ to Pd 0 , and leaching of the palladium was also significant [201]. The low redox stability of Pd 2+ in the presence of a large excess of alcohol reactant proved to be a general complication; another example is the formation of Pd nanoparticles from hydroxyapatite-supported PdCl 2 (PhCN) 2 during the aerobic oxidation of alcohols [74].…”

CeO2 Nanocrystalline-Supported Palladium Chloride: An Effective Catalyst for Selective Oxidation of Alcohols by Oxygen

“…However, these studies have only considered homogeneous catalysis; the applications of these catalytic systems (on an industrial scale) are limited due to the difficult recovery of the expensive metals and ligands from the reaction mixture. Heterogeneous catalysts do not pose these problems and the efficiency of various metals has been studied in this respect: Ru [8][9][10], Au [11], Pd [12][13][14][15][16] and, recently, Au-Pd/TiO 2 [17] catalysts were reported.…”