Copper catalyzed oxidation of amino acids

Szabina Góger , József S Pap , Dóra Bogáth , A. Jalila Simaan (1) , Gabor Speier , Michel Giorgi (2) , Jozsef Kaizer

1 ISM2 - Institut des Sciences Moléculaires de Marseille
2 AMU SPEC - Spectropôle - Aix Marseille Université

Copper(II) chloride and novel bis(1-amino(cyclo)alkane-1-carboxylato-j 2 N,O)copper(II) complexes as catalysts were studied in relation with enzymatic oxidation of amino acids. The oxidation of aminophosphonate derivative: (1-amino-1-methyl)ethylphosphonic acid was also investigated. Two bis(1-aminocycloalkane-1-carboxylato-j 2 N,O)copper(II) complexes were structurally characterized. Surprisingly, while the 1-aminocyclobutane-1-carboxylate complex has square planar (SP-4) copper(II) center with trans-orientated ligands, the 1-aminocyclohexane-1-carboxylate complex has l-carboxylato dimeric structure with square pyramidal (SPY-5) sites, one with cis-and one with trans-orientated ligands. Redox behavior of the bis(1-amino(cyclo)alkane-1-carboxylato-j 2 N,O)copper(II) complexes was also investigated. Catalytic oxidations were carried out in alkaline DMF-water mixtures using H 2 O 2 as oxidant and the complexes as catalysts. The observed potentials for the irreversible current peaks associated with the Cu(II) to Cu(I) reduction and the rates of the amino acid oxidations show inverse trend. This suggests that the Cu(II)/Cu(I) redox cycling due to the presence of H 2 O 2 plays important role in the peroxide/copper activation that in turn provides the observed products.

Domaines: Chimie

Szabina Góger, József S Pap, Dóra Bogáth, A. Jalila Simaan, Gabor Speier, et al.. Copper catalyzed oxidation of amino acids. Polyhedron, 2014, 73, pp.37-44. ⟨10.1016/j.poly.2014.02.007⟩. ⟨hal-02091411⟩