Copper complexes with bis(piperidinyl)methane (BP) and bis(quinolinyl)methane (BQ) ligands were investigated. A dinuclear carbonato-bridged copper(II) complex as well as a dinuclear copper(I) complex with BP ligands were structurally characterized. The reaction of a copper(I)-BP complex was investigated by low-temperature stopped-flow techniques, which showed that the very fast formation of a bis(μ-oxido)copper intermediate leads to an intramolecular ligand hydroxylation.[a]

The preparation of methylene‐bridged C2‐symmetric nitrogen‐heterocycles as a new class of ligands is described, including methylene‐bridged pyridines, quinolones, piperidines and pyrrolidines. These methylene‐bridged aromatic systems are obtained via a microwave assisted Ziegler‐type reaction. The separation of diastereomers and the application of the copper complexes of these ligands for cyclopropanation reactions proves the applicability of these new types of ligands.