Luft Jennifer A R, Meleson Kieche, Houk K N
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
Org Lett. 2007 Feb 15;9(4):555-8. doi: 10.1021/ol062751x. Epub 2007 Jan 25.
Transition structures of the 1,3-dipolar cycloaddition of substituted nitrile oxides with chiral homoallylic alcohols were explored with density functional theory (B3LYP/6-311+G(d,p)+CPCM(dichloromethane)//B3LYP/6-31+G(d)). The diastereoselectivity observed in these reactions was explained. The anti product is favored in both the thermal and magnesium-mediated reactions. Selectivity is predicted to increase in the presence of magnesium, in agreement with experimental results. The energetics of the magnesium-mediated reaction are similar to those previously found for allylic alcohols. [structure: see text].
采用密度泛函理论(B3LYP/6-311+G(d,p)+CPCM(二氯甲烷)//B3LYP/6-31+G(d))研究了取代腈氧化物与手性高烯丙醇的1,3-偶极环加成反应的过渡结构。解释了这些反应中观察到的非对映选择性。在热反应和镁介导的反应中,反式产物都占优势。预计在镁存在下选择性会增加,这与实验结果一致。镁介导反应的能量学与先前烯丙醇的能量学相似。[结构:见正文]