Studies toward practical synthesis of (20S)-camptothecin family through catalytic enantioselective cyanosilylation of ketones: improved catalyst efficiency by ligand-tuning

Enantioselective catalyst efficiency for the synthesis of the camptothecin family was improved through ligand-tuning. Key intermediates of two convergent syntheses of camptothecin (Curranʹs intermediate and Coreyʹs intermediate) were obtained in up to 10 g scale through the catalytic enantioselective cyanosilylation of ketones.