Quick Installation of a 1,4-Difunctionality via Regioselective Nickel-Catalyzed Reductive Coupling of Ynoates and Aldehydes
Sanjeewa K. Rodrigo and Hairong Guan*
*Department of Chemistry, University of Cincinnati, P.O. Box 21072, Cincinnati, Ohio 45221-0172, United States, Email: hairong.guanuc.edu
S. K. Rodrigo, H. Guan, J. Org. Chem., 2012, 77, 8303-8309.
DOI: 10.1021/jo301790q (free Supporting Information)
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An intermolecular reductive coupling of ynoates and aldehydes in the presence of a silane using catalytic amounts of Ni(COD)2, an N-heterocyclic carbene ligand, and PPh3 delivers invaluable silyl-protected γ-hydroxy-α,β-enoates. This methodology provides a quick entry to many other 1,4-difunctional compounds and oxygen-containing five-membered rings. The intermediacy of metallacycles in the catalytic process has been established.
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