Synthesis of Functionalized Olefins by Cross and Ring-Closing Metatheses
Abstract
The generation of olefins with electron-withdrawing functionality, such as α,β-unsaturated aldehydes, ketones, and esters, remains a difficult task in organic chemistry. A practical method to approach this problem would involve olefin metathesis, utilizing well-defined alkylidenes such as ((CF_3)_2MeCO)_2(ArN)Mo CH(t-Bu) (1) and (Pcy_3)_2Cl_2Ru CHPh (2). However, the generation of olefins with vinylic functionality through the use of cross-metathesis (CM) has met with limited success. In one of the few reports of this reaction, Crowe and Goldberg demonstrated that acrylonitrile participated in cross-metathesis reactions with a variety of terminal olefins. Other π-conjugated olefins, such as enones and enoic esters, were not functional group compatible with alkylidene 1 and failed to react with 2 in cross-metathesis. Recently, the highly active ruthenium-based olefin metathesis catalyst 3, which contains a 1,3-dimesityl-4,5-dihydro-imidazol-2-ylidene ligand, was found to efficiently catalyze the cross-metathesis of 1,1-geminally disubstituted olefins.7 Because ruthenium alkylidene 3 displayed unique activity toward previously metathesis-inactive substrates, we decided to investigate the metathesis of α-functionalized olefins. In this communication, we report the single-step synthesis of α-functionalized olefins by intermolecular cross-metathesis and intramolecular ring-closing metathesis using ruthenium alkylidene 3.
Additional Information
© 2000 American Chemical Society. Received November 11, 1999. Publication Date (Web): April 4, 2000. Support has been generously provided by the National Institutes of Health. The authors thank Thomas A. Kirkland, Helen E. Blackwell, Melanie S. Sanford, Tina M. Trnka, and Daniel J. O'Leary for useful discussions and encouragement. M.S. thanks Pharmacia & Upjohn for a graduate fellowship in synthetic organic chemistry. The authors also wish to thank Richard Pederson for a generous supply of compound 6.Attached Files
Supplemental Material - ja9939744_s.pdf
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Additional details
- Eprint ID
- 76812
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- CaltechAUTHORS:20170421-093813295
- NIH
- Pharmacia
- Upjohn Company
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2017-04-21Created from EPrint's datestamp field
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2021-11-15Created from EPrint's last_modified field