Olefin metathesis process employing bimetallic ruthenium complex with bridging hydrido ligands
View Patent ↗An olefin metathesis process for converting a reactant olefin or a mixture of reactant olefins into one or more product olefins that are different from the reactant olefin(s). The process employs a catalyst system containing a carbene-generating agent and a bimetallic ruthenium complex comprising one or more μ-hydrido bridging ligands, and optionally containing di(t-butyl)phosphine. The catalyst system is advantageously active at process temperatures greater than 90° C. Cyclization metathesis and ring-opening polymerization metathesis are preferred olefin metathesis processes.
1. A metathesis catalyst system comprising a bimetallic ruthenium-ligand complex represented by the following formula:
wherein each q is 1; each Q is independently selected from 6-electron donor arene ligands; wherein each n is the same and is 0, 1, or 2; wherein each Y is an anionic di(t-butyl)phosphido ligand, with the proviso that when n=0, then the catalyst system further comprises di(tertiary-butyl)phosphine and a carbene-generating agent that is represented by the following formula:
wherein each R is independently selected from hydrogen and monovalent C1-C20 hydrocarbyl groups and substituted variants thereof; or alternatively, wherein both R groups are bonded together to form a divalent C 3 -C 8 alkylene or divalent C 4 -C 7 arylene group, or substituted variant thereof; and wherein X is either hydroxyl or halogen.