"Electronic effects in oxidation reactions utilizing dinuclear copper c" by Armando M. Guidote Jr., Ronald L. Reyes et al.
 

Electronic effects in oxidation reactions utilizing dinuclear copper complexes with the Bis[3-[2-hydroxybenzylldeneamino)phenyll sulfone ligand

College

College of Science

Department/Unit

Chemistry

Document Type

Archival Material/Manuscript

Publication Date

2014

Abstract

Copper acetate and the ligands bis[3-(3-tert-butyl-2-hydroxy-5-methoxybenzylidene-amino)phenyl] sulfone and bis[3-(3,5-di-tert-butyl-2-hydroxybenzylideneamino)phenyl] sulfone were reacted to form the complexes with 2:1 copper:ligand ratio, Cu2[B(t-Bu) (OMe)BAPS](u-OCH3)2 (4) and with 2:2 copper:ligand ratio, Cu2[B(t-Bu)2BAPS]2 (5), respectively. Structures of 4 and 5 were determined based on IR, UV-Vis, and FAB-MS data in comparison with previously characterized related copper complexes. The two complexes 4 and 5 were utilized in the oxidation of the substrates 2,4- and 2,6-di-tert-butylphenol (dtbp) at -50C with H2O2 in CH2CI2. The coupling products are preferred in biphenol were achieved with the use 4 and 5, respectively. For 2,6-dtbp, yields of 1,900% and 400% of 3,3,5,5-tetra-tert-butyl-4,4-biphenol were realized utilizing 4 and respectively. These show that the methoxy groups activated the complex. Based on low temperature UV-vis results, a u-n2;n2-peroxo or a u-hydroperoxo intermediate was possibly formed by the reaction of 4 with the H2O2. This effected the oxidation of the 2,4-and 2,6- dtbp substrates but also resulted in the attack of other complexes which acted as substrates. A proposed oxidation mechanism using complex 4 and related complexes is presented.

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Disciplines

Chemistry

Keywords

Complex compounds; Oxidation

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