Total Syntheses of Aspidospermidine, <i>N</i> -Methylaspidospermidine, <i>N</i> -Acetylaspidospermidine, and Aspidospermine via a Tandem Cyclization of Tryptamine-Ynamide
Lu Yang, Siwen Huang, Rongkang Huang, Anbin Hou, Sen Zhang, Hongwei Su, Xiaohong Ding, Bin Lin, Maosheng Cheng, Yongxiang Liu
Abstract
The total syntheses of aspidospermidine, N-methylaspidospermidine, N-acetylaspidospermidine, and aspidospermine were achieved from a common pentacyclic indoline intermediate. The common pentacyclic indoline intermediate was synthesized on a gram scale through a Stork-enamine alkylation of 1H-pyrrolo[2,3-d]carbazole derivatives, which were prepared through a Brønsted acid-catalyzed tandem cyclization of tryptamine-ynamide. The scalable synthesis of 1H-pyrrolo[2,3-d]carbazole afforded facile access and a practical approach to the Aspidosperma indole alkaloid family.
Topics & Concepts
ChemistryTryptamineIndolineTandemCarbazoleIndole testEnamineQuinolineAlkylationCombinatorial chemistryOrganic chemistryStereochemistryCatalysisMaterials scienceBiochemistryComposite materialCatalytic C–H Functionalization MethodsAlkaloids: synthesis and pharmacologyChemical synthesis and alkaloids