Affiliation:
1. Asymmetric synthesis, catalysis laboratory Department of Chemistry. Central University of Tamil Nadu (CUTN). Tiruvarur 610 005 India
2. Department of Chemistry Satavahana University Karimnagar 505 001 TS India
Abstract
AbstractThis research showcases a methodology for crafting highly intricate hydrocarbazole spirooxindole frameworks endowed with three consecutive stereocenters. Achieved through a trienamine‐catalyzed remote [4+2]‐annulation reaction, the method's significance is underscored by synthesizing an extensive array of library molecules (up to 27 examples). These compounds mimic natural products, exhibit good yields (up to 85 %), exceptional diastereo‐, enantiomeric ratios (up to 17 : 1 dr, 99.9 : 0.1 er). The practicality of our strategy is further exemplified by successfully synthesizing a hexahydroepoxyethanocarbazole spirooxindole scaffold via a sequential [4+2]‐annulation/‐reduction/epoxidation‐cyclization reaction, achieving a 75 % overall yield, maintaining an excellent stereoselectivity (99.5 : 0.5 er).