Aerobic oxidation of aldehydes catalyzed by ε-Keggin type polyoxometalates [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu) as heterogeneous catalysts

Dorit Sloboda-Rozner, Karine Neimann, Ronny Neumann

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Polyoxometalates of the ε-Keggin structure [Mo12 VO392-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu), have been synthesized. While the nickel substituted compound was known, the cobalt, manganese and copper analogs are new. These ε-Keggin polyoxometalates are insoluble and, except for the nickel analog, could not be obtained in crystalline form. The IR spectra indicate that for cobalt and manganese substitution the compounds are isostructural to the nickel derivative. The ε-Keggin polyoxometalates were used as heterogeneous catalysts for the aerobic oxidation of aldehydes to carboxylic acids. The selectivity of the reaction was highly dependent on the identity of the aldehyde. Aliphatic linear aldehydes, e.g. octanal, and benzaldehyde react quantitatively and selectively to the respective carboxylic acids. 2-Methyl-undecanal reacted quite selectively yielding as minor product 2-undecanone by decarboxylation. 2-Phenylpropanal showed more significant β-methyl cleavage. Substrates with a variety of functional moieties such as myrtenal and 5-norbornene-2-carboxaldehyde yielded considerable amounts of formates via a Dakin type reaction and allylic oxidation products.

Original languageEnglish
Pages (from-to)109-113
Number of pages5
JournalJournal of Molecular Catalysis A: Chemical
Volume262
Issue number1-2
DOIs
Publication statusPublished - Feb 1 2007

Fingerprint

Aldehydes
aldehydes
Manganese
Carboxylic Acids
Cobalt
Nickel
Carboxylic acids
catalysts
carboxylic acids
Oxidation
oxidation
Catalysts
manganese
Formates
cobalt
Nickel compounds
nickel
nickel compounds
analogs
decarboxylation

Keywords

  • ε-Keggin polyoxometalate
  • Aldehyde
  • Oxidation

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology
  • Materials Science (miscellaneous)

Cite this

@article{930c19f0ee4c4f59871010a016630dce,
title = "Aerobic oxidation of aldehydes catalyzed by ε-Keggin type polyoxometalates [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu) as heterogeneous catalysts",
abstract = "Polyoxometalates of the ε-Keggin structure [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu), have been synthesized. While the nickel substituted compound was known, the cobalt, manganese and copper analogs are new. These ε-Keggin polyoxometalates are insoluble and, except for the nickel analog, could not be obtained in crystalline form. The IR spectra indicate that for cobalt and manganese substitution the compounds are isostructural to the nickel derivative. The ε-Keggin polyoxometalates were used as heterogeneous catalysts for the aerobic oxidation of aldehydes to carboxylic acids. The selectivity of the reaction was highly dependent on the identity of the aldehyde. Aliphatic linear aldehydes, e.g. octanal, and benzaldehyde react quantitatively and selectively to the respective carboxylic acids. 2-Methyl-undecanal reacted quite selectively yielding as minor product 2-undecanone by decarboxylation. 2-Phenylpropanal showed more significant β-methyl cleavage. Substrates with a variety of functional moieties such as myrtenal and 5-norbornene-2-carboxaldehyde yielded considerable amounts of formates via a Dakin type reaction and allylic oxidation products.",
keywords = "ε-Keggin polyoxometalate, Aldehyde, Oxidation",
author = "Dorit Sloboda-Rozner and Karine Neimann and Ronny Neumann",
year = "2007",
month = "2",
day = "1",
doi = "10.1016/j.molcata.2006.08.046",
language = "English",
volume = "262",
pages = "109--113",
journal = "Journal of Molecular Catalysis A: Chemical",
issn = "1381-1169",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Aerobic oxidation of aldehydes catalyzed by ε-Keggin type polyoxometalates [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu) as heterogeneous catalysts

AU - Sloboda-Rozner, Dorit

AU - Neimann, Karine

AU - Neumann, Ronny

PY - 2007/2/1

Y1 - 2007/2/1

N2 - Polyoxometalates of the ε-Keggin structure [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu), have been synthesized. While the nickel substituted compound was known, the cobalt, manganese and copper analogs are new. These ε-Keggin polyoxometalates are insoluble and, except for the nickel analog, could not be obtained in crystalline form. The IR spectra indicate that for cobalt and manganese substitution the compounds are isostructural to the nickel derivative. The ε-Keggin polyoxometalates were used as heterogeneous catalysts for the aerobic oxidation of aldehydes to carboxylic acids. The selectivity of the reaction was highly dependent on the identity of the aldehyde. Aliphatic linear aldehydes, e.g. octanal, and benzaldehyde react quantitatively and selectively to the respective carboxylic acids. 2-Methyl-undecanal reacted quite selectively yielding as minor product 2-undecanone by decarboxylation. 2-Phenylpropanal showed more significant β-methyl cleavage. Substrates with a variety of functional moieties such as myrtenal and 5-norbornene-2-carboxaldehyde yielded considerable amounts of formates via a Dakin type reaction and allylic oxidation products.

AB - Polyoxometalates of the ε-Keggin structure [Mo12 VO39(μ2-OH)10H2{XII(H2O)3}4] (X = Ni, Co, Mn and Cu), have been synthesized. While the nickel substituted compound was known, the cobalt, manganese and copper analogs are new. These ε-Keggin polyoxometalates are insoluble and, except for the nickel analog, could not be obtained in crystalline form. The IR spectra indicate that for cobalt and manganese substitution the compounds are isostructural to the nickel derivative. The ε-Keggin polyoxometalates were used as heterogeneous catalysts for the aerobic oxidation of aldehydes to carboxylic acids. The selectivity of the reaction was highly dependent on the identity of the aldehyde. Aliphatic linear aldehydes, e.g. octanal, and benzaldehyde react quantitatively and selectively to the respective carboxylic acids. 2-Methyl-undecanal reacted quite selectively yielding as minor product 2-undecanone by decarboxylation. 2-Phenylpropanal showed more significant β-methyl cleavage. Substrates with a variety of functional moieties such as myrtenal and 5-norbornene-2-carboxaldehyde yielded considerable amounts of formates via a Dakin type reaction and allylic oxidation products.

KW - ε-Keggin polyoxometalate

KW - Aldehyde

KW - Oxidation

UR - http://www.scopus.com/inward/record.url?scp=33846120680&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846120680&partnerID=8YFLogxK

U2 - 10.1016/j.molcata.2006.08.046

DO - 10.1016/j.molcata.2006.08.046

M3 - Article

AN - SCOPUS:33846120680

VL - 262

SP - 109

EP - 113

JO - Journal of Molecular Catalysis A: Chemical

JF - Journal of Molecular Catalysis A: Chemical

SN - 1381-1169

IS - 1-2

ER -