Synthesis and Activity of Six-Membered Cyclic Alkyl Amino Carbene–Ruthenium Olefin Metathesis Catalysts
Adrian E. Samkian, Yan Xu, Scott C. Virgil, Ki‐Young Yoon, Robert H. Grubbs
Abstract
Ru–cyclic alkyl amino carbene (Ru–CAAC) olefin metathesis catalysts perform extraordinarily in metathesis macrocyclization and ethenolysis, but previous studies have been limited to the use of five-membered CAAC (CAAC-5) ligands. In this work, we synthesized a different group of ruthenium catalysts with more σ-donating and π-accepting six-membered CAAC (CAAC-6) ligands, and their metathesis activity was probed through initiation studies, ring-closing metathesis (RCM), cross-metathesis, and ethenolysis. These catalysts display higher initiation rates than analogous Ru–CAAC-5 complexes but demonstrate lower activity in RCM and ethenolysis.
Topics & Concepts
CarbeneChemistryRutheniumMetathesisCatalysisAcyclic diene metathesisOlefin metathesisAlkylRing-closing metathesisRing-opening metathesis polymerisationSalt metathesis reactionMedicinal chemistryCombinatorial chemistryOrganic chemistryPolymerizationPolymerSynthetic Organic Chemistry MethodsN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic Cross-Coupling Reactions