Highly Enantioselective Direct Reductive Coupling of Conjugated Alkynes and α-Ketoesters via Rhodium-Catalyzed Asymmetric Hydrogenation
Jong-Rock Kong, Ming-Yu Ngai and Michael J. Krische*
*Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, Email: mkrischemail.utexas.edu
J.-R. Kong, M.-Y. Ngai, M. J. Krische, J. Am. Chem. Soc., 2006, 128, 718-719.
DOI: 10.1021/ja056474l (free Supporting Information)
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Highly enantioselective direct catalytic reductive couplings of 1,3-enynes to activated ketones such as ethyl pyruvate have been achieved by using chirally modified cationic rhodium catalysts in the presence of hydrogen to afford dienylated α-hydroxy esters with exceptional levels of regio- and enantiocontrol.
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Y.-T. Hong, C.-W. Cho, E. Skucas, M. J. Krische, Org. Lett., 2007, 9, 3745-3748.
M.-Y. Ngai, A. Barchuk, M. J. Krische, J. Am. Chem. Soc., 2007, 129, 280-281.
Enantioselective Reductive Coupling of 1,3-Enynes to Glyoxalates Mediated by Hydrogen: Asymmetric Synthesis of β,γ-Unsaturated α-Hydroxy EstersKey Words