The Discovery of Quinoxaline-Based Metathesis Catalysts from Synthesis of Grazoprevir (MK-5172).

Olefin metathesis (OM) is a reliable and practical synthetic methodology for challenging carbon–carbon bond formations. While existing catalysts can effect many of these transformations, the synthesis and development of new catalysts is essential to increase the application breadth of OM and to achieve improved catalyst activity. The unexpected initial discovery of a novel olefin metathesis catalyst derived from synthetic efforts toward the HCV therapeutic agent grazoprevir (MK-5172) is described. This initial finding has evolved into a class of tunable, shelf-stable ruthenium OM catalysts that are easily prepared and exhibit unique catalytic activity.