A Practical O2-Oxidation of Functionalized Alcohols Producing Carboxylic Acids Catalyzed by the Pd–C/Pb(OAc)2 System

Abstract

The Pd–C/Pb(OAc)2 system catalyzes selective O2-oxidation of ArCH(R)CH2OH to ArCH(R)COOH (useful intermediates for drug synthesis) in high yields without contamination of ArCOOH. The turnover number (substrate/Pd) is improved to 85 and >1800 by recycling the catalyst and using a special reactor, respectively. Alkanols are also efficiently oxidized to alkanoic acids by the title catalyst system.

Oxidation of Alcohols with Molecular Oxygen on Solid Catalysts

“…Ru and Rh are usually applied without promoters. [21][22][23][24][25][26][27][28][29] Besides Bi and Pb, a variety of promoter metals have been suggested, including Cd, 30,31 Co, 30,31 Cu, 32 Se, 33 Ce, 33,34 Te, 35 Sn, 36,37 Au, 36,38 and Ru. 36,39 The non-noble metal promoters are inactive under reaction conditions, and their deposition onto the active sites should result in lower oxidation rates.…”

“…Still, promotion of Pt or Pd may lead to a considerable rate enhancement (Scheme 1) [40][41][42] and to a remarkable shift in the product distribution (Scheme 2). 32,37,43 The bimetallic catalysts can be prepared by simultaneous deposition and reduction of the metal precursors onto a suitable support. 33,44,45 The most commonly used method is, however, the deposition and reduction of promoter onto a supported Pt or Pd catalyst.…”

Selective oxidation of glycerol with oxygen using mono and bimetallic catalysts based on Au, Pd and Pt metals

“…However, using an oxidation process applied to aqueous solutions using air on recyclable catalysts will lower the cost and also will be beneficial from environmental point of view. In recent years, many studies have been focused on the oxidation of alcohols [1][2][3][4][5][6][7][8] and polyols [9][10][11][12][13][14] to chemical intermediates. The big challenge associated with these catalytic oxidation reactions is to control and direct the reaction pathway to the desired products.…”

A simple discrimination of the promoter effect in alcohol oxidation and dehydrogenation over platinum and palladium

“…The promoter metals, such as Bi, Pb, Te, Sn, and others, have generated the most interest [22][23][24][25][26]. The promoter metals alone are inactive in alcohol oxidation under the mild conditions applied; still, they induce sometimes spectacular rate enhancement [27][28][29] or a shift in the product distribution [21,30,31]. Despite the intensive effort by several research groups, the real nature of the promoter effect is still debated.…”