摘要

The mechanisms of the title reaction have been studied by density functional theory (DFT) method. Two possible reaction channels, including the non-catalyzed channel (channel 1) and the catalyzed channel promoted by peroxo tungsten compound (channel 2), have been studied at the B3LYP/[LANL2DZ/6-31G(d, p)] level. The calculated results indicate that the catalyzed channel is more energy favorable than the non-catalyzed channel, and the energy barriers of channel 2 are not high for the experimental temperature, thus, we think the peroxo tungsten compound would play an important role in making the title reaction easier to occur. Moreover, solvation effect has been suggested using single point frequency calculations at the B3LYP/[LANL2DZ/6-311++G(2d, 2p)] level in water using IEF-PCM model. At last, the regeneration mechanism of catalyst has been investigated at the B3LYP/[LANL2DZ/6-31G(d, p)] level, and the highest energy barrier is only 26.17 kcal/mol, so the catalyst should be easy to regenerate in our system.