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Intramolecular Ni-Mediated Cyclizations with α,ω-Dienals

2001; Wiley; Volume: 2001; Issue: 7 Linguagem: Inglês

10.1002/1099-0690(200104)2001

1434-193X

Gabriel García-Gómez, Josep M. Moretó,

Asymmetric Synthesis and Catalysis

European Journal of Organic ChemistryVolume 2001, Issue 7 p. 1359-1369 Full Paper Intramolecular Ni-Mediated Cyclizations with α,ω-Dienals Gabriel García-Gómez, IIQAB “Josep Pascual Vila” CID, CSIC, c/ J. Girona 18−26, 08034 Barcelona, Spain, Fax: (internat.) + 34-3/204-5904Search for more papers by this authorJosep M. Moretó, jmmqob@cid.csic.es IIQAB “Josep Pascual Vila” CID, CSIC, c/ J. Girona 18−26, 08034 Barcelona, Spain, Fax: (internat.) + 34-3/204-5904Search for more papers by this author Gabriel García-Gómez, IIQAB “Josep Pascual Vila” CID, CSIC, c/ J. Girona 18−26, 08034 Barcelona, Spain, Fax: (internat.) + 34-3/204-5904Search for more papers by this authorJosep M. Moretó, jmmqob@cid.csic.es IIQAB “Josep Pascual Vila” CID, CSIC, c/ J. Girona 18−26, 08034 Barcelona, Spain, Fax: (internat.) + 34-3/204-5904Search for more papers by this author First published: 05 March 2001 https://doi.org/10.1002/1099-0690(200104)2001:7 3.0.CO;2-7Citations: 4Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract Fifteen α,ω-dienals and one α-en-ω-ynal were prepared. These substrates were treated with Ni(COD)2/TMSCl under carbonylative and noncarbonylative conditions, with subsequent methanol quenching of the resulting metal intermediates to afford different types of cycloadducts. From the compounds thus obtained, it is concluded that the reaction proceeds through an intermediate (π-allyl)Ni complex, which readily cyclises in a “metallo-ene”-type reaction. The different pathways were characterised by further carbonyl insertion or by protonolysis, resulting either in cyclopentanone formation (insertion followed by β-elimination) when under carbon monoxide gas, or in single cyclization when not (or, even better, when in the presence of protic acids). Coordination of the distal olefin has been found essential for either of the two processes to proceed. Thus, coordinating heteroatoms (N,S), excessive tether length and particular substituents hampering satisfactory double bond chelation all disrupt the process, with the ketals of the original aldehyde (occasionally as Michael adducts) largely being recovered in such cases. Citing Literature Volume2001, Issue7April 2001Pages 1359-1369 RelatedInformation