Enantioselective Michael Addition of Photogenerated <i>o</i>‑Quinodimethanes to Enones Catalyzed by Chiral Amino Acid Esters

The first example of a photoexcitated amine-catalyzed process for asymmetric Michael addition of o-quinodimethanes to enones is described. In the presence of simple chiral amino acid esters, a variety of Michael adducts were generally obtained in good yields and excellent stereoselectivities. This strategy can be successfully applied to 3-substituted-2-cyclohexenones and provides an asymmetric access to all-carbon quaternary centers. Furthermore, the high stereocontrol was explained by means of density-functional theory (DFT) calculations.本文报道了首例用于邻醌二甲烷（o-quinodimethanes）与烯酮（enones）间不对称迈克尔加成（asymmetric Michael addition）的光激发胺催化反应体系。在简单手性氨基酸酯（chiral amino acid esters）的作用下，多数反应可获得收率良好、立体选择性优异的多种迈克尔加成产物（Michael adducts）。该策略可成功应用于3-取代-2-环己烯酮（3-substituted-2-cyclohexenones）类底物，为全碳季碳中心（all-carbon quaternary centers）的不对称构建提供了可行路径。此外，本研究通过密度泛函理论（density-functional theory, DFT）计算阐明了其高立体控制的内在机制。