Yb(OTf)3-Promoted ZnCl2-Catalyzed Conia-Ene Reaction of Linear β-Alkynic β-Dicarbonyls
Yu Liu, Ren-Jie Song, Jin-Heng Li*
*Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education), Hunan Normal University, Changsha 410081, P. R. of China , Email: jhlihunnu.edu.cn
Y. Liu, R.-J. Song, J.-H. Li, Synthesis, 2010, 3663-3669.
A solvent-free ytterbium(III) triflate promoted, zinc(II) chloride catalyzed Conia-ene reaction allows the construction of cyclic enones. In the presence of zinc(II) chloride and ytterbium(III) triflate, a variety of linear β-alkynic β-keto esters and β-diketones were cyclized under neat conditions in good yields. The selectivity toward five- or six-membered-ring carbocycles depends on substituents at the terminal alkynes.
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