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A practical method for enantioselective synthesis of all-carbon quaternary stereogenic centers through NHC-Cu-catalyzed conjugate additions of alkyl- and arylzinc reagents to beta-substituted cyclic enones.
J Am Chem Soc. 2006 Jun 07; 128(22):7182-4.JA

Abstract

We present the first examples of Cu-catalyzed enantioselective conjugate additions of alkyl- and arylzinc reagents to unactivated cyclic beta-substituted enones. Transformations are promoted in the presence of 2.5-15 mol % of a readily available chiral NHC-based Cu complex, affording the desired products bearing all-carbon quaternary stereogenic centers in 67-->98% yield and in up to 97% ee. Catalytic enantioselective reactions can be carried out on a benchtop, with undistilled solvent and commercially available (not further purified) Cu salts. Mechanistic models, accounting for the observed levels and trends in enantioselectivity are provided.

Authors+Show Affiliations

Lee KS
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Brown MK
No affiliation info available
Hird AW
No affiliation info available
Hoveyda AH
No affiliation info available

MeSH

AlkanesAlkylationCarbonCatalysisCopperCyclizationKetonesMolecular StructureOrganometallic CompoundsStereoisomerismZinc

Pub Type(s)

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

Language

eng

PubMed ID

16734469

Citation

Lee, Kang-sang, et al. "A Practical Method for Enantioselective Synthesis of All-carbon Quaternary Stereogenic Centers Through NHC-Cu-catalyzed Conjugate Additions of Alkyl- and Arylzinc Reagents to Beta-substituted Cyclic Enones." Journal of the American Chemical Society, vol. 128, no. 22, 2006, pp. 7182-4.
Lee KS, Brown MK, Hird AW, et al. A practical method for enantioselective synthesis of all-carbon quaternary stereogenic centers through NHC-Cu-catalyzed conjugate additions of alkyl- and arylzinc reagents to beta-substituted cyclic enones. J Am Chem Soc. 2006;128(22):7182-4.
Lee, K. S., Brown, M. K., Hird, A. W., & Hoveyda, A. H. (2006). A practical method for enantioselective synthesis of all-carbon quaternary stereogenic centers through NHC-Cu-catalyzed conjugate additions of alkyl- and arylzinc reagents to beta-substituted cyclic enones. Journal of the American Chemical Society, 128(22), 7182-4.
Lee KS, et al. A Practical Method for Enantioselective Synthesis of All-carbon Quaternary Stereogenic Centers Through NHC-Cu-catalyzed Conjugate Additions of Alkyl- and Arylzinc Reagents to Beta-substituted Cyclic Enones. J Am Chem Soc. 2006 Jun 7;128(22):7182-4. PubMed PMID: 16734469.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - A practical method for enantioselective synthesis of all-carbon quaternary stereogenic centers through NHC-Cu-catalyzed conjugate additions of alkyl- and arylzinc reagents to beta-substituted cyclic enones. AU - Lee,Kang-sang, AU - Brown,M Kevin, AU - Hird,Alexander W, AU - Hoveyda,Amir H, PY - 2006/6/1/pubmed PY - 2007/7/25/medline PY - 2006/6/1/entrez SP - 7182 EP - 4 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 128 IS - 22 N2 - We present the first examples of Cu-catalyzed enantioselective conjugate additions of alkyl- and arylzinc reagents to unactivated cyclic beta-substituted enones. Transformations are promoted in the presence of 2.5-15 mol % of a readily available chiral NHC-based Cu complex, affording the desired products bearing all-carbon quaternary stereogenic centers in 67-->98% yield and in up to 97% ee. Catalytic enantioselective reactions can be carried out on a benchtop, with undistilled solvent and commercially available (not further purified) Cu salts. Mechanistic models, accounting for the observed levels and trends in enantioselectivity are provided. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/16734469/A_practical_method_for_enantioselective_synthesis_of_all_carbon_quaternary_stereogenic_centers_through_NHC_Cu_catalyzed_conjugate_additions_of_alkyl__and_arylzinc_reagents_to_beta_substituted_cyclic_enones_ DB - PRIME DP - Unbound Medicine ER -