A Soluble Polymer-Bound Ruthenium Carbene Complex: A Robust and Reusable Catalyst for Ring-Closing Olefin Metathesis

Poly(ethylene glycol)(PEG)-bound Ru carbene complex 3, prepared from functionalized styrene 1 and Grubbs catalyst 2, exhibits remarkable stability and catalyzes the ring-closing metathesis of a variety of α,ω-dienes, and leads to the formation of five-, six-, seven-, and eight-membered carbo- and heterocycles. The catalyst can be completely recovered and repeatedly reused (up to eight runs) with minimal loss of activity.