<i>exo</i>-Selective Asymmetric Diels-Alder Reaction of 2,4-Dienals and Nitroalkenes by Trienamine Catalysis
作者:Zhi-Jun Jia、Quan Zhou、Qing-Qing Zhou、Peng-Qiao Chen、Ying-Chun Chen
DOI:10.1002/anie.201102013
日期:2011.9.5
Raising the HOMO: 2,4‐Dienals can react with nitroalkenes in trienamine‐catalyzed asymmetric Diels–Alder reactions (see scheme). Crucial for the success is raising the HOMO energy of the diene through the introduction of appropriate substituents. The reaction exhibits unusually high enantioselectivity and exo selectivity; endo addition is possibly disfavored because of the electrostatic repulsion shown
提高HOMO:2,4-二烯醛可以与三烯胺催化的不对称Diels-Alder反应中的硝基烯烃反应(参见方案)。成功的关键是通过引入适当的取代基来提高二烯的HOMO能量。该反应表现出异常高的对映选择性和外切选择性。由于方案中所示的静电排斥作用,可能不利于内含物的添加。