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Highly enantioselective direct reductive coupling of conjugated alkynes and alpha-ketoesters via rhodium-catalyzed asymmetric hydrogenation.
J Am Chem Soc. 2006 Jan 25; 128(3):718-9.JA

Abstract

Catalytic hydrogenation of 1,3-enynes 1a-7a in the presence of ethyl pyruvate and related activated ketones using chirally modified cationic rhodium catalysts results in reductive coupling to afford dienylated alpha-hydroxy esters 1b-7b and 3c-3f with exceptional levels of regio- and enantiocontrol. These studies represent the first highly enantioselective direct catalytic reductive couplings of alkynes to ketones. As illustrated by the conversion of 6b to 6c-6h, the diene containing the side chain of the coupling products is subject to diverse chemo- and regioselective manipulation. Reductive coupling of enyne 6a and ethyl pyruvate using elemental deuterium provides the monodeuterated product deuterio-6b, consistent with a catalytic mechanism involving alkyne-carbonyl oxidative coupling followed by hydrogenolytic cleavage of the resulting oxametallacycle, as corroborated by ESI-MS analysis.

Authors+Show Affiliations

Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16417351

Citation

Kong, Jong-Rock, et al. "Highly Enantioselective Direct Reductive Coupling of Conjugated Alkynes and Alpha-ketoesters Via Rhodium-catalyzed Asymmetric Hydrogenation." Journal of the American Chemical Society, vol. 128, no. 3, 2006, pp. 718-9.
Kong JR, Ngai MY, Krische MJ. Highly enantioselective direct reductive coupling of conjugated alkynes and alpha-ketoesters via rhodium-catalyzed asymmetric hydrogenation. J Am Chem Soc. 2006;128(3):718-9.
Kong, J. R., Ngai, M. Y., & Krische, M. J. (2006). Highly enantioselective direct reductive coupling of conjugated alkynes and alpha-ketoesters via rhodium-catalyzed asymmetric hydrogenation. Journal of the American Chemical Society, 128(3), 718-9.
Kong JR, Ngai MY, Krische MJ. Highly Enantioselective Direct Reductive Coupling of Conjugated Alkynes and Alpha-ketoesters Via Rhodium-catalyzed Asymmetric Hydrogenation. J Am Chem Soc. 2006 Jan 25;128(3):718-9. PubMed PMID: 16417351.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Highly enantioselective direct reductive coupling of conjugated alkynes and alpha-ketoesters via rhodium-catalyzed asymmetric hydrogenation. AU - Kong,Jong-Rock, AU - Ngai,Ming-Yu, AU - Krische,Michael J, PY - 2006/1/19/pubmed PY - 2006/4/7/medline PY - 2006/1/19/entrez SP - 718 EP - 9 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 128 IS - 3 N2 - Catalytic hydrogenation of 1,3-enynes 1a-7a in the presence of ethyl pyruvate and related activated ketones using chirally modified cationic rhodium catalysts results in reductive coupling to afford dienylated alpha-hydroxy esters 1b-7b and 3c-3f with exceptional levels of regio- and enantiocontrol. These studies represent the first highly enantioselective direct catalytic reductive couplings of alkynes to ketones. As illustrated by the conversion of 6b to 6c-6h, the diene containing the side chain of the coupling products is subject to diverse chemo- and regioselective manipulation. Reductive coupling of enyne 6a and ethyl pyruvate using elemental deuterium provides the monodeuterated product deuterio-6b, consistent with a catalytic mechanism involving alkyne-carbonyl oxidative coupling followed by hydrogenolytic cleavage of the resulting oxametallacycle, as corroborated by ESI-MS analysis. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/16417351/Highly_enantioselective_direct_reductive_coupling_of_conjugated_alkynes_and_alpha_ketoesters_via_rhodium_catalyzed_asymmetric_hydrogenation_ L2 - https://doi.org/10.1021/ja056474l DB - PRIME DP - Unbound Medicine ER -