New copper(II) dimer with 3-(2-hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione and its catalytic activity in cyclohexane and benzyl alcohol oxidations

✍ Scribed by Kamran T. Mahmudov; Maximilian N. Kopylovich; M. Fátima C. Guedes da Silva; Paweł J. Figiel; Yauhen Yu. Karabach; Armando J.L. Pombeiro

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 444 KB
• Volume: 318
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2009.11.006

✦ Synopsis

nitrophenylhydrazo)pentane-2,4-dione complexes Azoderivatives of ␤-diketones Copper X-ray structure Oxidation of cyclohexane Oxidation of benzyl alcohol TEMPO a b s t r a c t 3-(2-Hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione (H 2 L, 1) was synthesized by azocoupling of diazonium salts of 2-hydroxy-4-nitroaniline with pentane-2,4-dione and shown to exist in the hydrazone tautomeric form in the free state and in its new dicopper(II) complex [Cu 2 (H 2 O) 2 (-L) 2 ] (2) whose X-ray crystal structure was determined. Complex 2 acts as a catalyst, under mild conditions, for the peroxidative oxidation (with H 2 O 2 ) of cyclohexane to cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide, in MeCN/H 2 O, and for the aerobic TEMPO-mediated selective oxidation of benzylic alcohols to the corresponding aldehydes, thus showing that azoderivatives of ␤-diketones can be the suitable ligands for such types of reactions.