Gold(I)-catalyzed Conia-ene reaction of beta-ketoesters with alkynes

J Am Chem Soc. 2004 Apr 14;126(14):4526-7. doi: 10.1021/ja049487s.

Abstract

The intramolecular addition of beta-ketoesters to unactivated alkynes under neutral conditions and at room temperature is described. The method employs triphenylphosphinegold(I) cation as a catalyst for the formation of exo-methylenecycloalkanes. Both monocyclic and bicyclic cyclopentanes and cyclohexanes can be formed in excellent yields and with good diastereoselectivity.