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Supramolecular control of monooxygenase reactivity in a copper(ii) cryptate.

Dalton Trans. 2016 Jul 05;45(27):11109-19

Authors: Chaloner L, Khomutovskaya A, Thomas F, Ottenwaelder X

Abstract

We report a detailed investigation of the formation and self-decomposition of Cu(ii)-hydroperoxo intermediates under the influence of second-coordination-sphere features provided by a cryptand. In solution, an equilibrium between two copper complexes with square-planar and square-pyramidal geometries was identified. Upon addition of H2O2/Et3N, two copper(ii)-hydroperoxo intermediates formed at different rates. Their decomposition via self-oxidation was probed by deuterating select positions on the cryptand. This led to a small kinetic isotope effect of 1.5. Mass spectrometry analysis of the demetallated organic products is consistent with a direct oxygen-atom transfer to a tertiary amine on the cryptand, forming an N-oxide, unlike other models of copper mononuclear monooxygenase enzymes.

PMID: 27328176 [PubMed - indexed for MEDLINE]