α-Haloamides are a very important class of carbonyl compounds, and widely exist in a range of natural products and bioactive molecules. Herein, the realization of the tandem oxidation/halogenation of ynamides by employing the zinc halide as both the catalyst and the halogen source is described, thus avoiding the use of other external halogenating reagents. This method allows the practical synthesis of a variety of valuable α-haloamides in moderate to good yields.

Doping energies of Ca, Ba, Sm and Zr in CeO 2 systems and influences of dopings on oxygen ion migration energies and vacancy formation energies were studied using DFT and DFT＋U methods. The calculated results showed that the doping energies increased with doping cation radius for doped CeO 2 systems without oxygen vacancies, and for doped CeO 2 systems with oxygen vacancies, the doping energies were related to the valence of the doping cations besides their radius. Calculations on electronic structures of various doped CeO 2 systems showed that Fermi level shifted to the high energy in reduced CeO 2 , Zr-and Sm-doped CeO 2 systems, however, in Ca-and Ba-doped CeO 2 systems, negative charges due to the substitution of Ca 2＋ and Ba 2＋ with lower chemical valence for Ce 4＋ and positive charges due to the formation of oxygen ion vacancy were neutralized, so Fermi level scarcely shifted. Ce 3＋ existed in the reduced CeO 2 system and the Zr-doped CeO 2 system, which would lead to mixed conductivity with ion and electron one, and electron state of Ce 3＋ layed between Ce4f and O2p. However, the reduction of Ce 4＋ was restrained in Ca-, Ba-and Sm-doped CeO 2 systems. The migration of an oxygen vacancy was investigated using the nudged elastic band method. The calculated results indicated that a straightforward migration path between two adjacent oxygen sites for oxygen vacancy hopping was obtained. For Ca-, Ba-, Sm-and Zr-doped CeO 2 systems, the migration energies of oxygen ions were smaller than that of CeO 2 system. In these doped CeO 2 systems, the migration energy of oxygen ions for Ba was the smallest and its doping energy are the largest, so Ba was maybe introduced through adding the third class dopant in experiment.

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