title: A copper complex bearing a TEMPO moiety as catalyst for the aerobic oxidation of primary alcohols.
abstract: A new bifunctional, triazine-based ligand has been designed with the aim to generate a copper(II) complex holding a TEMPO (2,2,6,6-tetramethylpiperidinyloxy) moiety. The coordination compound obtained from the ligand 4-(2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethoxy)-6-(4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)-N,N-diphenyl-1,3,5-triazin-2-amine (pypzt-1) and copper(II) bromide (i.e. complex 8) is capable of catalysing the selective, aerobic oxidation of benzyl alcohol to 84% of benzaldehyde in 24 h. This "galactose oxidase activity" of the copper/TEMPO complex is observed as well for the conversion of the non-activated alkyl alcohol octan-1-ol to octanal with a yield of 29% after the same reaction time. The single-crystal X-ray structure of 8 shows that its crystal lattice contains [Cu(I)Br(2)](-) anions which appear to be stabilised by means of both anion-pi and hydrogen bonding interactions. In addition, the solid state structure of 8 exhibits (lone-pair)-pi interactions between the nitrogen atom of an acetonitrile molecule and a triazine ring. The magnetic properties of 8 have been investigated by EPR and magnetic susceptibility measurements.
authors.affiliation: Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300, RA, Leiden, The Netherlands.
authors.forename: Zhengliang
authors.initials: Z
authors.lastname: Lu
authors.forename: José Sánchez
authors.initials: JS
authors.lastname: Costa
authors.forename: Olivier
authors.initials: O
authors.lastname: Roubeau
authors.forename: Ilpo
authors.initials: I
authors.lastname: Mutikainen
authors.forename: Urho
authors.initials: U
authors.lastname: Turpeinen
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Teat
authors.forename: Patrick
authors.initials: P
authors.lastname: Gamez
authors.forename: Jan
authors.initials: J
authors.lastname: Reedijk