Simply Assembled and Recyclable Polymer-Supported Olefin Metathesis Catalysts

Polymer-supported ruthenium catalysts (PCy3)2Ru(C(H)Ph)Cl2, (PCy3)Ru(IMes)(C(H)Ph)Cl2, and (PCy3)Ru(SIMes)(C(H)Ph)Cl2, where IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene and SIMes = 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene, have been prepared and found to be effective “boomerang” catalysts for ring-closing metathesis. They are recyclable, show comparable or better reactivity than their homogeneous counterparts, tolerate functional groups, and perform very well with dienes and moderately well with highly hindered substrates.