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Enantioselective Carbonyl Propargylation by Iridium-Catalyzed Transfer Hydrogenative Coupling of Alcohols and Propargyl Chlorides

Authors

  • Dr. Sang Kook Woo,

    1. University of Texas at Austin, Department of Chemistry and Biochemistry, 1 University Station—A5300, Austin, TX 78712-1167 (USA)
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  • Dr. Laina M. Geary,

    1. University of Texas at Austin, Department of Chemistry and Biochemistry, 1 University Station—A5300, Austin, TX 78712-1167 (USA)
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  • Prof. Michael J. Krische

    Corresponding author
    1. University of Texas at Austin, Department of Chemistry and Biochemistry, 1 University Station—A5300, Austin, TX 78712-1167 (USA)
    • University of Texas at Austin, Department of Chemistry and Biochemistry, 1 University Station—A5300, Austin, TX 78712-1167 (USA)
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  • We acknowledge the Robert A. Welch Foundation (F-0038), the NSF (CHE-1008551), and the Government of Canada’s Banting Postdoctoral Fellowship Program (L.M.G.) for financial support. We thank Dr. Taichiro Touge of Takasago for the generous donation of segphos ligands.

Abstract

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It takes alkynes! Exposure of propargyl chlorides to primary benzylic alcohols in the presence of [Ir(cod){(R)-segphos}]OTf (cod=1,5-cyclooctadiene, segphos=5,5′-bis(diphenylphosphino)-4,4′-bi-1,3-benzodioxole, Tf=trifluoromethanesulfonyl) results in hydrogen exchange to give allenyliridium–aldehyde pairs that combine to form products of propargylation with high ee value (see scheme). The reaction can also be conducted using aldehydes.

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