DFT Study On Mechanism Of Several Transition Metal-Catalyzed Asymmetric Reaction

In this paper, the chiral bisoxazoline-copper(I)-catalyzed asymmetric AllylicAcyloxylation, the Chiral Bisoxazoline-Zinc(I)-Catalyze Enantioselective Henry Reactions, respectively, by means of the nonlocal density functional method (DFT). The mechanisms of these asymmetric reactions are discussed in detail.Density Functional Theory Studies on Catalytic Enantioselective AIIylicAcyloxylation of Olefins with Chiral Copper(I) Complexes and tert-ButylPerbenzoateThe chiral bisoxazoline-copper(I)-catalyzed asymmetric allylic acyloxylation of olefins and tert-butyl perbenzoate was studied by density functional theory (DFT). All the intermediates and the transition states were optimized completely at the B3LYP/6-31G and B3LYP/6-31G(d) levels. As shown, this asymmetric allylic oxidation is exothermic. The turnover-limiting step for the asymmetric allylic oxidation is the formation of chiral catalyst-allyl perbenzoate complexes. The dominant product predicted theoretically is S- but-3-en-2-yl benzoate, which is in agreement with the experiment.Density Functional Theory (DFT) on the ChiralBisoxazoline-Zinc(I)-Catalyze Enantioselective Henry Reactions of Nitromethaneand o -keto EsterAll the intermediates and the transition states were optimized completely at the B3LYP/6-31G level. As shown, this asymmetric reaction is exothermic. The turnover-limiting step for the asymmetric Henry reaction is the formation of chiral catalyst- (methyl 2-hydroxy-2-methyl-3-nitropropanoate) complexes or the formation of chiral catalyst-(3-hydroxy-3-methoxy-4-nitrobutan-2-one) complexes. The dominant product predicted theoretically is R-methyl2-hydroxy-2-methyl-3-nitropropanoate, which is in agreement with the experiment.