A DFT and AIM Study of the Proline-Catalyzed Asymmetric Cross-Aldol Addition of Acetone to Isatins: A Rationalization for the Reversal of Chirality
作者:Rodrigo J. Corrêa、Simon J. Garden、Gaetano Angelici、Claudia Tomasini
DOI:10.1002/ejoc.200700944
日期:2008.2
effects that control the enantioselectivity in the cross-aldol addition of acetone to isatin catalyzed by L-proline have been studied by means of DFT and AIM calculations. This reaction results in a reversal of enantioselectivity compared with the corresponding cross-aldol addition to 4,6-dibromoisatin and aldehydes. DFT calculations of the cross-aldol transition states indicate that product formation
已经通过 DFT 和 AIM 计算研究了空间和立体电子效应,这些效应控制在 L-脯氨酸催化下丙酮与靛红的交叉羟醛加成中的对映选择性。与相应的交叉羟醛添加到 4,6-二溴靛红和醛相比,该反应导致对映选择性的逆转。跨羟醛过渡态的 DFT 计算表明,对于底物靛红和 4,6-二溴靛红,产物的形成遵循不同的途径。在靛红的情况下,由于立体电子效应导致 S 对映体相对于 R 对映体具有较低能量的过渡态,因此 S 对映体受到青睐。相比之下,丙酮与 4 的交叉羟醛加成,