In Situ Generation of Ru-Based Metathesis Catalyst. A Systematic Study

A systematic study for the in situ generation of Ru-based metathesis catalysts was described. Assembly of commercially available and inexpensive reagents [Ru­(p-cymene)­Cl2]2, SIPr·HCl, and n-BuLi led to the formation of 18 electron arene-ruthenium complexes that, in the presence of additives such as alkynes, cyclopropenes, and diazoesters, generated highly selective and efficient catalytic systems applicable to a variety of olefin metathesis transformations. Notably, we were able to achieve a productive TON of 4500 for the self-metathesis of methyl oleate, a reaction which could be easily upscaled to 2 kg.