Synthesis of Cyclic Alkenylsiloxanes by Semihydrogenation: A Stereospecific Route to (Z)‐Alkenyl Polyenes |
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| Authors: | Bryony L. Elbert Diane S. W. Lim Haraldur G. Gudmundsson Jack A. O'Hanlon Dr. Edward A. Anderson |
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| Affiliation: | Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, U.K. Fax: (+44)?1865‐285002 |
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| Abstract: | Cyclic alkenylsiloxanes were synthesized by semihydrogenation of alkynylsilanes—a reaction previously plagued by poor stereoselectivity. The silanes, which can be synthesized on multigram scale, undergo Hiyama–Denmark coupling to give (Z)‐alkenyl polyene motifs found in bioactive natural products. The ring size of the silane is crucial: five‐membered cyclic siloxanes also couple under fluoride‐free conditions, whilst their six‐membered homologues do not, enabling orthogonality within this structural motif. |
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| Keywords: | alkynes cross‐coupling hydrogenation natural products silanes |
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