Ruthenium Olefin Metathesis Catalysts with Six-Membered Chelating Dithioacetal Ligands: Synthesis and Reactivity

Ruthenium sulfur-chelated benzylidenes possessing five-membered chelating architectures exhibiting latency and excellent thermal and photochemical activation behavior in various metathesis reactions are well known. On the other hand, six-membered sulfur-Ru-chelates (Ru-S) are much rarer. Herein, we describe a study of the synthesis, characterization, and catalytic properties of four new cis-dichlorido ruthenium dithioacetal-chelated complexes. As expected for sulfur-chelated benzylidenes, the X-ray structures of the complexes disclosed cis-dichloro configurations for all the complexes. The catalytic profiles of these complexes were systematically studied for benchmark RCM and ROMP reactions and provided findings on latency and activation based on chelating dithioacetal groups.