Construction of Eight-Membered Carbocycles through Gold Catalysis with Acetylene-Tethered Silyl Enol Ethers


  • This work was supported by Grants-in-Aid for Scientific Research on Challenging Exploratory Research, MEXT and ACT-C, JST to M.S. and by Grant-in-Aid for Young Scientists (Start-up), JSPS to T.I. H.I. thanks JSPS for support through a scholarship.


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Semihollow triethynylphosphanes were synthesized and employed as ligands in the gold-catalyzed 8-exo-dig cyclization of acetylene-tethered silyl enol ethers to obtain eight-membered-ring carbocycles (see scheme). The gold–phosphane catalysts promoted either the annulation toward bicyclic structures or the cyclization of acyclic molecules to form nonfused carbocycles. Tf=Trifluoromethylsulfonyl.