Heteroscorpionate ligands of the bis(pyrazolyl)methane family have been applied in the stabilisation of terminal copper tosyl nitrenes. These species are highly active intermediates in the copper-catalysed direct C-H amination and nitrene transfer. Novel perfluoroalkyl-pyrazolyl- and pyridinyl-containing ligands were synthesized to coordinate to a reactive copper nitrene centre. Four distinct copper tosyl nitrenes were prepared at low temperatures by the reaction with SO tBuPhINTs and copper(I) acetonitrile complexes. Their stoichiometric reactivity has been elucidated regarding the imination of phosphines and the aziridination of styrenes. The formation and thermal decay of the copper nitrenes were investigated by UV/Vis spectroscopy of the highly coloured species. Additionally, the compounds were studied by cryo-UHR-ESI mass spectrometry and DFT calculations. In addition, a mild catalytic procedure has been developed where the copper nitrene precursors enable the C-H amination of cyclohexane and toluene and the aziridination of styrenes.

Chemoenzymatic cascades enable reactions with the high productivity of chemocatalysts and high selectivity of enzymes. Nevertheless, the combination of these different fields of catalysis is prone to mutual deactivation of metal‐ and biocatalysts. In this study, a one‐pot sequential two‐step catalytic cascade reaction was successfully implemented for the synthesis of a methylene‐bridged bis(2‐substituted benzofuran). In the first step, a palladium‐free Sonogashira reaction is used for the synthesis of a benzofuran derivative. In the subsequent step, the formed 2‐substituted benzofuran is hydroxylated by the monooxygenase P450 BM3 variant (A74S‐F87V‐L188Q) and undergoes further elimination reactions. The study proofs that combination of Cu scorpionate catalyzed Sonogashira cross‐coupling and P450 mediated oxidation is possible and results in up to 84 % yield of the final product. The oxidation reaction is boosted by capturing inhibiting reaction components.

A series of bis(pyrazolyl)methane copper complexes were found to catalyze a fast palladium‐free Sonogashira coupling reaction of several iodoarenes with terminal alkynes such as phenylacetylene, propargyl benzyl ether, and (tert‐butyl‐dimethyl)silylacetylene. These reactions proceed with CuCl2·2H2O (10 mol‐%) under aerobic conditions and the corresponding chelate ligand (10 mol‐%), with its tailored facial coordination mode, is crucial for the success of the reaction. The coupling can also be carried out in water with liquid aryl halides and a phase‐transfer catalyst.

The ligand class of tridentate bis(pyrazolyl)methanes was extended via the syntheses of HC(3,5‐EtPz)2Py. This ligand is the first of its kind with a homogeneous 3,5‐functionalization with large substituents. On the basis of 3,5‐functionalized ligands we were able to synthesize 15 novel complexes with FeII, ZnII, and CuII salts. Herein we present an extensive coordination chemistry study, that focuses on the influences of different metals, ligands, and counterions on the coordination mode and on the spin state in case of FeII complexes.