Cu(II) bipyridine and phenantroline complexes: Tailor-made catalysts for the selective oxidation of tetralin

• Published in: Applied catalysis. A, General General, 2009-06, Vol.360 (2), p.218-225
• Main Authors: Louis, B., Detoni, C., Carvalho, N.M.F., Duarte, C.D., Antunes, O.A.C.
• Format: Article
• Language: English
• Subjects: 1,10-Phenantroline; 2,2′-Bipyridine; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Hydrogen peroxide; Mononuclear Cu(II) complexes; Partial oxidation; Tetralin; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2009.03.022

Mononuclear 2,2′-bipyridine and 1,10-phenantroline mononuclear Cu(II) complexes have been synthesized, and their structure determined by ESI-MS. These complexes have been tested in the partial oxidation of tetralin (1,2,3,4-tetrahydronaphthalene), using hydrogen peroxide as oxidant in acetonitrile/water solvent. [Cu(bipy) 2Cl]Cl catalyst was able to oxidize tetralin at room temperature, at 62.1% conversion into 1-tetralol and 1-tetralone at 91% selectivity (81% in 1-tetralone). Mononuclear Cu(II) complexes have been synthesized, and their structure thoroughly characterized by electrospray ionization mass spectrometry (ESI-MS). These 2,2′-bipyridine and 1,10-phenantroline mononuclear Cu(II) complexes have been tested as catalysts in the partial oxidation of tetralin (1,2,3,4-tetrahydronaphthalene), using hydrogen peroxide as oxidant in acetonitrile/water as solvent. The complexes [Cu(bipy) 3]Cl 2·6H 2O ( 1), [Cu(bipy) 2Cl]Cl·5H 2O ( 2), [Cu(bipy)Cl 2] ( 3), [Cu(phen) 3]Cl 2·6H 2O ( 4), [Cu(phen) 2Cl]Cl·5H 2O ( 5), [Cu(phen)Cl 2] ( 6) were able to oxidize tetralin at room temperature, at high degrees of conversion (62.1% with 2) into α-tetralol and α-tetralon at 91% selectivity (81% in 1-tetralon). Depending on nature and number of ligands (bipyridine or phenantroline) surrounding Cu 2+ cation, one was able to tailor both the activity toward tetralin oxidation, and the selectivity toward 1-tetralol and 1-tetralone products, but also to raise the yield in valuable α-tetralone.