New Approaches to Olefin Cross-Metathesis
Abstract
New methodology for the selective cross-metathesis (CM) of terminal olefins employing ruthenium benzylidene 1 is described.1 CM with symmetric internal olefins was found to provide a useful means for homologating terminal olefins to protected allylic alcohols, amines, and esters. Due to the limited commercial availability of symmetric internal olefins, a two-step CM procedure was developed in which terminal olefins were first homodimerized prior to the CM reaction. Terminal olefins with allylic methyl substituents were observed to provide CM products in diminished yield albeit with markedly improved trans-selectivity. Reaction rates were measured for CM reactions utilizing butenediol and allyl alcohol derivatives, and the results demonstrated distinct advantages in reaction rate and stereoselectivity for reactions employing the disubstituted olefins. In the course of studies of substrates with allylic oxygen substituents, a new CM application was discovered involving the metathesis of acrolein acetal derivatives with terminal olefins. Acrolein acetals, including asymmetric variants derived from tartaric acid, proved to be exceptionally robust and trans-selective CM substrates. In related work, a pinacol-derived vinyl boronate was also found to be a reactive CM partner, providing a novel means for converting terminal olefins into precursors for the Suzuki coupling reaction.
Additional Information
© 2000 American Chemical Society. Received 23 August 1999. Published online 21 December 1999. Published in print 1 January 2000. Work at Caltech was generously supported by grants from the National Institutes of Health (NIH) and Zeneca Pharmaceuticals. Work at Pomona College was supported by grants from the National Science Foundation (NSF). H.E.B. thanks the ACS Division of Organic Chemistry for a Graduate Fellowship (supported by Pfizer, Inc.). D.J.O. thanks Pomona College for provision of a Steele junior faculty leave. R.A.W. thanks the Caltech SURF Program and the Pomona College Chemistry Department for a summer fellowship. Dr. Katsukiyo Miura is acknowledged for his assistance in the acrolein acetal cross-metathesis portion of this work. We thank the referees for their insightful comments.Attached Files
Supplemental Material - ja993063u_s.pdf
Supplemental Material - ja993063u_sa.pdf
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Additional details
- Eprint ID
- 77504
- Resolver ID
- CaltechAUTHORS:20170516-131732124
- NIH
- Zeneca Pharmaceuticals
- NSF
- Pfizer, Inc.
- Caltech Summer Undergraduate Research Fellowship (SURF)
- Pomona College
- Created
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2017-05-16Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field