425369-97-7Relevant academic research and scientific papers
Dimethylanilinic N-Oxides and Their Oxygen Surrogacy Role in the Formation of a Putative High-Valent Copper-Oxygen Species
Diaz, Daniel E.,Bhadra, Mayukh,Karlin, Kenneth D.
supporting information, p. 13746 - 13750 (2019/10/14)
The reaction of p-cyano-N,N-dimethylaniline N-oxide, an O-atom donor, with different copper(I) complexes (at room temperature and in acetone) indicates the formation via O-atom transfer of a high-valent copper oxyl species, CuII-O?, a putative key intermediate in the catalytic cycle of copper-containing monooxygenases. The formation of p-cyano-N-hydroxymethyl-N-methylaniline and p-cyano-N-methylaniline as the main products of the reaction highlight the capability of this species to hydroxylate strong C-H bonds (bond dissociation energy ～90 kcal/mol). A plausible mechanism for the reactivity of this catalytic system is proposed.
Contrasting copper-dioxygen chemistry arising from alike tridentate alkyltriamine copper(I) complexes
Liang, Hong-Chang,Zhang, Christiana Xin,Henson, Mark J.,Sommer, Roger D.,Hatwell, Karen R.,Kaderli, Susan,Zuberbuehler, Andreas D.,Rheingold, Arnold L.,Solomon, Edward I.,Karlin, Kenneth D.
, p. 4170 - 4171 (2007/10/03)
Copper(I)-dioxygen interactions are of great interest due to their role in biological O2-processing as well as their importance in industrial oxidation processes. We describe here the study of systems which lead to new insights concerning the factors which govern Cu(II)-μ-η2:η2 (side-on) peroxo versus Cu(III)-bis-μ-oxo species formation. Drastic differences in O2-reactivity of Cu(I) complexes which differ only by a single -CH3 versus -H substituent on the central amine of the tridentate ligands employed are observed. [Cu(MeAN)]B(C6F5)4 (1) (MeAN = N,N,N′,N′,N′-pentamethyl-dipropylenetriamine) reacts with O2 at -80 °C to form almost exclusively the side-on peroxo complex [{CuII(MeAN)}2(O2)]2+ (3) in CH2Cl2, tetrahydrofuran, acetone, and diethyl ether solvents, as characterized by UV-vis and resonance Raman spectroscopies. In sharp contrast, [Cu(AN)]B(C6F5)4 (2) (AN = 3, 3′-iminobis(N,N-dimethyl-propylamine) can support either Cu2O2 structures in a strongly solvent-dependent manner. Extreme behavior is observed in CH2Cl2 solvent, where 1 reacts with O2 giving 3, while 2 forms exclusively the bis-μ-oxo species [{CuIII(AN)}2(O)2]2+ (4Oxo). Stopped-flow kinetics measurements also reveal significant variations in the oxygenation reactions of 1 versus 2, including the observations that 4Oxo forms much faster than does 3; the former decomposes quickly, while the latter is quite stable at 193 K. The solvent-dependence of the bis-μ-oxo versus side-on peroxo preference observed for 2 is opposite to that reported for other known copper(I) complexes; the factors which may be responsible for the unusual behavior of 1/O2 versus 2/O2 (possibly N-H hydrogen bonding in the AN chemistry) are suggested. The factors which affect bis-μ-oxo versus side-on peroxo formation continue to be of interest. Copyright
