ETH Zurich, Laboratory for Organic Chemistry, D-CHAB, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland) http://www.wennemers.ethz.ch.
Angew Chem Int Ed Engl. 2015 Jul 6;54(28):8193-7. doi: 10.1002/anie.201502976. Epub 2015 Jun 1.
Oxindoles with adjacent tetrasubstituted stereocenters were obtained in high yields and stereoselectivities by organocatalyzed conjugate addition reactions of monothiomalonates (MTMs) to isatin-derived N-Cbz ketimines. The method requires only a low catalyst loading (2 mol %) and proceeds under mild reaction conditions. Both enantiomers are accessible in good yields and excellent stereoselectivities by using either Takemoto's catalyst or a cinchona alkaloid derivative. The synthetic methodology allowed establishment of a straightforward route to derivatives of the gastrin/cholecystokinin-B receptor antagonist AG-041R.
通过有机催化的单硫代丙二酸单酯（MTMs）与色胺衍生的 N-Cbz 亚胺的共轭加成反应，高收率和立体选择性地得到了具有相邻四取代立体中心的氧化吲哚。该方法仅需要低催化剂负载量（2 mol%），并在温和的反应条件下进行。使用 Takemoto 催化剂或金鸡纳生物碱衍生物都可以以良好的收率和优异的立体选择性获得两种对映体。该合成方法为胃泌素/胆囊收缩素-B 受体拮抗剂 AG-041R 的衍生物建立了一条直接途径。
