title: Total synthesis of (S)-(+)-imperanene. Effective use of regio- and enantioselective intramolecular carbon-hydrogen insertion reactions catalyzed by chiral dirhodium(II) carboxamidates.
abstract: The total synthesis of (S)-(+)-imperanene, a natural product found in Chinese medicine, has been completed in 12 steps from a commercially available cinnamic acid. The key step is highly enantioselective carbon-hydrogen insertion from a diazoacetate using a chiral dirhodium(II) carboxamidate catalyst. An elimination process essential to the construction has been optimized to avoid intramolecular Friedel-Crafts alkylation.
authors.affiliation: Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA. mdoyle@u.arizona.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Doyle
authors.forename: Wenhao
authors.initials: W
authors.lastname: Hu
authors.forename: Marcela V
authors.initials: MV
authors.lastname: Valenzuela
mesh_terms: D000478:Alkylation; D002384:Catalysis; D002934:Cinnamates / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008516:Medicine, Chinese Traditional; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D002934:Cinnamates; D009942:Organometallic Compounds; D010636:Phenols; C093767:imperanene; C029010:cinnamic acid; D012238:Rhodium