Center for Catalysis, Department of Chemistry, Aarhus University , 8000 Aarhus C, Denmark.
Org Lett. 2013 Jun 21;15(12):3010-3. doi: 10.1021/ol401204a. Epub 2013 Jun 3.
The synthesis of optically active, carboannulated dihydronaphthoquinone and naphthoquinone derivatives with up to four stereogenic centers is demonstrated by H-bond-directed, trienamine-mediated [4 + 2]-cycloadditions. The outcome of the reaction between 2,4-dienals and 1,4-naphthoquinones is controlled by the substituent in the 2-position of the 1,4-naphthoquinone. In the case of sterically demanding 2-substituted derivatives, dihydronaphthoquinones are obtained. However, when a hydrogen atom is present in the 2-position, a subsequent oxidation of the initially formed cycloadducts occurs yielding naphthoquinones.
通过氢键导向的三烯胺介导的[4+2]-环加成反应，展示了具有多达四个立体中心的手性、碳环化的二氢萘醌和萘醌衍生物的合成。反应产物由 1,4-萘醌 2-位取代基控制 2,4-二醛和 1,4-萘醌之间的反应。对于空间位阻较大的 2-取代衍生物，得到二氢萘醌。然而，当 2-位存在一个氢原子时，最初形成的环加成产物会发生随后的氧化，生成萘醌。
