Ruthenium byproducts from ring-closing metathesis reactions can be removed by refluxing the crude reaction mixture with resin-bound triphenylphosphine oxide (TPPO) in toluene or by stirring with dimethyl sulfoxide (DMSO) and silica gel at room temperature. Residual levels of ruthenium can be achieved that are as low as 0.04 μg per 5 mg of product when a combination of TPPO, DMSO, and silica gel is used. The polymer-bound TPPO retained its efficiency after being recycled six times.
Bibliographical noteFunding Information:
We gratefully acknowledge the financial support of the National Cancer Institute (CA84173) for this work. We would like to thank Dr. Eric Munson and Loren Joseph Schieber for carrying out the 31P MAS NMR measurements. We also wish to convey our gratitude to Dr. Gwendolyn L. Macpherson, Director of the Plasma Analytical Laboratory at the University of Kansas, for carrying out the ICP-MS measurements.
Copyright 2008 Elsevier B.V., All rights reserved.
- Dimethyl sulfoxide
- Polymer-bound triphenylphosphine oxide
- Ring-closing metathesis
- Ruthenium byproducts
- Silica gel