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.

Au → M bonds promote catalytic alkyne hydrofunctionalisation.

The impact of metalloligands on Au catalysed alkyne hydrofunctionalisation is studied. Ambiphilic PMP-type ligands (M = Cu, Ag, Zn) stabilise Au → M bonds including unprecedented Au → Zn interactions. The Lewis acidity of Au increases in the order Cu < Ag < Zn promoting catalytic cycloisomerisation of propargylamide 14.