Cyclometalated Z‑Selective Ruthenium Metathesis Catalysts with Modified N‑Chelating Groups

In order to design improved ruthenium catalysts for Z-selective olefin metathesis reactions, four cyclometalated catalysts with new chelated architectures were synthesized, structurally characterized, and tested in metathesis assays. The mechanism of formation of each was explored using DFT calculations. Of note, two complexes are derived from activation of a tertiary C–H bond, and one features a four-membered chelating architecture. In addition, two dipivalate complexes that did not undergo further C–H activation were isolated and studied to elucidate information about the factors affecting cyclometalation.