Catalytic Asymmetric Synthesis of Tertiary Alkyl Chlorides
2007; Wiley; Volume: 46; Issue: 6 Linguagem: Inglês
10.1002/anie.200604312
ISSN1521-3773
AutoresElaine C. Lee, Kevin M. McCauley, Gregory C. Fu,
Tópico(s)Synthesis and Catalytic Reactions
ResumoAngewandte Chemie International EditionVolume 46, Issue 6 p. 977-979 Communication Catalytic Asymmetric Synthesis of Tertiary Alkyl Chlorides† Elaine C. Lee, Elaine C. Lee Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this authorKevin M. McCauley Dr., Kevin M. McCauley Dr. Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this authorGregory C. Fu Prof. Dr., Gregory C. Fu Prof. Dr. [email protected] Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this author Elaine C. Lee, Elaine C. Lee Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this authorKevin M. McCauley Dr., Kevin M. McCauley Dr. Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this authorGregory C. Fu Prof. Dr., Gregory C. Fu Prof. Dr. [email protected] Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Fax: (+1) 617-324-3611Search for more papers by this author First published: 22 January 2007 https://doi.org/10.1002/anie.200604312Citations: 46 † We thank Michael Choi for preliminary studies and Luke Firmansjah and Dr. Peter Mueller for an X-ray crystallographic investigation. Support has been provided by the NIH (National Institute of General Medical Sciences: R01-GM57034 and F32-GM069154 (fellowship for K.M.M.); National Cancer Institute (training grant CA009112), Merck, and Novartis. Funding for the MIT Department of Chemistry Instrumentation Facility has been furnished in part by NSF CHE-9808061 and NSF DBI-9729592. Read 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 onEmailFacebookTwitterLinkedInRedditWechat Graphical Abstract Ketenes are coupled with 2,2,6,6-tetrachlorocyclohexanone in a catalytic asymmetric method for the synthesis of tertiary α-chloroesters (see scheme). This complements recent progress in the generation of secondary α-halocarbonyl compounds. Supporting Information Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z604312_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. References 1For leading references, see: 1aM. Marigo, K. A. Jørgensen, Chem. Commun. 2006, 2001–2011; 1bP. M. Pihko, Angew. Chem. 2006, 118, 558–561; Angew. Chem. Int. Ed. 2006, 45, 544–547; 1cG. K. S. Prakash, P. Beier, Angew. Chem. 2006, 118, 2228–2230; Angew. Chem. Int. Ed. 2006, 45, 2172–2174; 1dS. France, A. Weatherwax, T. Lectka, Eur. J. Org. Chem. 2005, 475–479; 1eM. Oestreich, Angew. Chem. 2005, 117, 2376–2379; Angew. Chem. Int. Ed. 2005, 44, 2324–2327; 1fH. Ibrahim, A. Togni, Chem. Commun. 2004, 1147–1155; 1gG. W. Gribble, Acc. Chem. Res. 1998, 31, 141–152. 2N. De Kimpe, R. Verhe, The Chemistry of α-Haloketones, α-Haloaldehydes, and α-Haloimines, Wiley, New York, 1988. 3For two examples, see: 3aM. P. Brochu, S. P. Brown, D. W. C. MacMillan, J. Am. Chem. Soc. 2004, 126, 4108–4109; 3bN. Halland, A. Braunton, S. Bachmann, M. Marigo, K. A. Jørgensen, J. Am. Chem. Soc. 2004, 126, 4790–4791. 4For leading references to the synthesis and the utility of enantioenriched tertiary alkyl halides, see: D. J. Ramon, M. Yus, Curr. Org. Chem. 2004, 8, 149–183. 5As far as we are aware, the only catalytic asymmetric methods for the synthesis of tertiary α-chlorocarbonyl compounds employ 1,3-dicarbonyls or 1,3-ketophosphonates as substrates: 5aL. Hintermann, A. Togni, Helv. Chim. Acta 2000, 83, 2425–2435; 5bH. Ibrahim, F. Kleinbeck, A. Togni, Helv. Chim. Acta 2004, 87, 605–610; 5cM. Marigo, N. Kumaragurubaran, K. A. Jørgensen, Chem. Eur. J. 2004, 10, 2133–2137; 5dG. Bartoli, M. Bosco, A. Carlone, M. Locatelli, P. Melchiorre, L. Sambri, Angew. Chem. 2005, 117, 6375–6378; Angew. Chem. Int. Ed. 2005, 44, 6219–6222; 5eN. Shibata, J. Kohno, K. Takai, T. Ishimaru, S. Nakamura, T. Toru, S. Kanemasa, Angew. Chem. 2005, 117, 4276–4279; Angew. Chem. Int. Ed. 2005, 44, 4204–4207; 5fL. Bernardi, K. A. Jørgensen, Chem. Commun. 2005, 1324–1326. 6Yamamoto et al. recently described a synthesis of enantioenriched tertiary α-chloroketones by the reaction of cyclic silyl enol ethers with a stoichiometric chiral chlorinating agent (48–98 % ee; three examples): Y. Zhang, K. Shibatomi, H. Yamamoto, J. Am. Chem. Soc. 2004, 126, 15038–15039. 7For examples of natural products that bear chiral tertiary α-chlorocarbonyl groups, see: 7aT. Henkel, A. Zeeck, J. Antibiot. 1991, 44, 665–669; 7bK. Shiomi, H. Nakamura, H. Iinuma, H. Naganawa, K. Isshiki, T. Takeuchi, H. Umezawa, Y. Iitaka, J. Antibiot. 1986, 39, 494–501; 7cK. Shiomi, H. Nakamura, H. Iinuma, H. Naganawa, T. Takeuchi, H. Umezawa, Y. Iitaka, J. Antibiot. 1987, 40, 1213–1219; 7dS. Gomi, S. Ohuchi, T. Sasaki, J. Itoh, M. Sezaki, J. Antibiot. 1987, 40, 740–749. 8For medicinal-chemistry studies of compounds that bear chiral tertiary α-chlorocarbonyl groups, see: 8ataxol derivatives: R. C. Pandey, L. K. Yankov, A. Poulev, R. Nair, S. Caccamese, J. Nat. Prod. 1998, 61, 57–63; 8bcamptothecin analogues: X. Wang, X. Zhou, S. M. Hecht, Biochemistry 1999, 38, 4374–4381; 8csqualene synthase inhibitors: I. J. S. Fairlamb, J. M. Dickinson, R. O'Connor, S. Higson, L. Grieveson, V. Marin, Bioorg. Med. Chem. 2002, 10, 2641–2656. 9For examples of syntheses wherein a key intermediate is a chiral tertiary α-chlorocarbonyl compound, see: 9aT. C. McMorris, M. D. Staake, M. J. Kelner, J. Org. Chem. 2004, 69, 619–623; 9bM. E. Jung, M. H. Parker, J. Org. Chem. 1997, 62, 7094–7095. 10For pioneering work on the catalytic asymmetric synthesis of secondary α-chloroesters from ketenes, see: 10aH. Wack, A. E. Taggi, A. M. Hafez, W. J. Drury III, T. Lectka, J. Am. Chem. Soc. 2001, 123, 1531–1532; 10bS. France, H. Wack, A. E. Taggi, A. M. Hafez, T. R. Wagerle, M. H. Shah, C. L. Dusich, T. Lectka, J. Am. Chem. Soc. 2004, 126, 4245–4255. 11For an overview of the chemistry of ketenes, see: T. T. Tidwell, Ketenes, Wiley-Interscience, New York, 2006. 12For leading references, see: G. C. Fu, Acc. Chem. Res. 2004, 37, 542–547. 13Hexachloroacetone (hexachloro-2-propanone) is an attractive chlorinating agent owing to its relatively low cost ($71 kg−1 from Aldrich). As far as we are aware, there are no reports of its use in catalytic asymmetric chlorination reactions. 14See reference [10]. When we apply Lectka's method to the chlorination of phenyl ethyl ketene, the desired ester is produced in 30 % yield and 5 % ee. 15N-Chloropyridines are known. For example, see: J. R. L. Smith, L. C. McKeer, J. M. Taylor, J. Chem. Soc. Perkin Trans. 2 1987, 1533–1537. 16This mechanism resembles the Brønsted acid pathway that we have proposed for certain asymmetric additions to ketenes that are catalyzed by planar-chiral derivatives of DMAP (i.e., Cl takes the place of H). For example, see: S. L. Wiskur, G. C. Fu, J. Am. Chem. Soc. 2005, 127, 6176–6177. 17We have suggested that PPY* and related compounds serve as nucleophilic catalysts for several reactions that involve ketenes.[12] 18Lectka favors a chiral-enolate pathway for his benzoylquinine-catalyzed asymmetric synthesis of secondary α-chloroesters from ketenes.[10] 19For a review of nonlinear effects in asymmetric catalysis, see: H. B. Kagan, T. O. Luukas in Comprehensive Asymmetric Catalysis (Eds.: ), Springer, New York, 1999, chap. 4.1. 20Although we have not ruled out reaction by mean of a chiral chlorinating agent (top of Scheme 1), on the basis of circumstantial evidence (the stereochemical outcome, the reactivity profile, and the effect of concentration on ee), we favor the chiral-enolate pathway (bottom of Scheme 1). Citing Literature Volume46, Issue6January 29, 2007Pages 977-979 ReferencesRelatedInformation
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