Design and Synthesis of Sulfur-Containing Tetradentate\nLigands for Ir-Catalyzed Asymmetric Hydrogenation of Ketones

Developing\nhighly active and enantioselective ligands for the asymmetric\nhydrogenation of ketones has consistently attracted significant attention\nfrom scientists. A series of novel tetradentate sulfur-containing\nligands, termed as f-thiophamidol, were successfully designed and\nsynthesized which exhibited excellent performance in the asymmetric\nhydrogenation of simple ketones (up to 99% yield, 99% ee) and α-substituted\nβ-keto sulfonamides (up to 99% yield, 99% ee, 99:1 dr). The\nsubsequent successful gram-scale experiments with high TON demonstrated\nthe immense potential application value of this system in synthesizing\ndrug molecules.