Abstract
In this short review, we focus on the synthesis and applications of new phosphite-bearing ruthenium complexes in olefin metathesis. These complexes were designed to take advantage of a known synergistic effect between strong σ-donating NHC ligands and π-acidic phosphites. The resulting catalysts display higher stability compared to their phosphine-containing congeners. A comparative summary of their use in ring-closing metathesis, cross metathesis, and ring-opening metathesis polymerization, as well as DFT calculations describing our mechanistic understanding, are presented.