Department of Chemistry, Sungkyunkwan University, Suwon, 440-746, Korea.
Angew Chem Int Ed Engl. 2017 Feb 6;56(7):1835-1839. doi: 10.1002/anie.201611466. Epub 2017 Jan 18.
Water enables new catalytic reactions for otherwise unreactive substrate systems. Under the "on water" reaction conditions, extremely unreactive β,β-disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all-carbon-substituted quaternary centers. The developed "on water" protocol was successfully applied for the scalable one-pot syntheses of chiral GABA analogs with all-carbon quaternary stereogenic centers at the β-position, which might show highly interesting pharmaceutical properties.
水能够为原本无反应性的底物系统带来新的催化反应。在“水相”反应条件下，极其无反应性的β,β-二取代硝基烯烃能够在手性双恶唑啉催化剂的作用下，与二硫代丙二酸酯进行对映选择性迈克尔加成反应，以高对映体过量的方式得到具有全碳取代季碳原子的高对映体富集的迈克尔加成产物的两种对映异构体。所开发的“水相”方法成功地应用于具有β位全碳季立体中心的手性 GABA 类似物的可规模化一锅合成，它们可能具有非常有趣的药物性质。
