The bridge towards a more stable and active side-on-peroxido (Cu(µ-η:η-O)) complex as a tyrosinase model system.

A novel dinucleating bis(pyrazolyl)methane ligand was developed for tyrosinase model systems. After ligand synthesis, the corresponding Cu(I) complex was synthesized and upon oxygenation, formation of a µ-η:η peroxido complex could be observed and monitored using UV/Vis-spectroscopy. Due to the high stability of this species even at room temperature, a molecular structure of the complex could be characterized single-crystal XRD.

Cyclic Ureate Tantalum Catalyst for Preferential Hydroaminoalkylation with Aliphatic Amines: Mechanistic Insights into Substrate Controlled Reactivity.

The efficient and catalytic amination of unactivated alkenes with simple secondary alkyl amines is preferentially achieved. A sterically accessible, ,-chelated cyclic ureate tantalum catalyst was prepared and characterized by X-ray crystallography. This optimized catalyst can be used for the hydroaminoalkylation of 1-octene with a variety of aryl and alkyl amines, but notably enhanced catalytic activity can be realized with challenging -alkyl secondary amine substrates.