Synthesis of Optically Active 2<i>H</i>-Thiopyrano[2,3-<i>b</i>]quinolines with Three Contiguous Stereocenters<i>via</i>an Organocatalytic Asymmetric Tandem Michael-Henry Reaction
Optically active 2H‐thiopyrano[2,3‐b]quinolines with threecontiguousstereocenters have been synthesized via a chiral bifunctional squaramide‐catalyzed tandem Michael–Henry reaction between 2‐mercaptoquinoline‐3‐carbaldehydes and nitroolefins. The reactions proceed with excellent diastereo‐ and enantioselectivity to give the title compounds in high yields with high levels of diastereo‐ and enantioselectivity
光学活性的2 H-硫代吡喃并[2,3- b ]喹啉具有三个连续的立体中心,是通过2-巯基喹啉-3-甲醛与硝基烯烃之间的手性双官能方酰胺催化的迈克尔-亨利串联反应合成的。反应以极好的非对映和对映选择性进行,以高收率得到标题化合物,同时具有高水平的非对映和对映选择性(分别高达> 99/1 dr和> 99%ee)。