title: Domino Pd-catalyzed Heck cyclization and bismuth-catalyzed hydroamination: formal synthesis of elacomine and isoelacomine.
abstract: The formal synthesis of hemiterpene spirooxindole alkaloids elacomine (1) and isoelacomine (2) is described. Heck reaction of protected iodoanilines with 5,6-dihydro-2H-pyran-2-one or six-membered unsaturated lactams was investigated. The coupling product was readily converted to a carbamoyl chloride with an incorporated diene unit. The spiro(pyrrolidine-3,3'-oxindole) skeleton, which corresponds to the carbon skeleton of 1 and 2, was efficiently constructed from this intermediate by using a domino palladium-catalyzed Heck reaction and bismuth-catalyzed hydroamination. An isolated byproduct of the reaction could also be converted to the spirooxindole skeleton.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Haruhi
authors.initials: H
authors.lastname: Kamisaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nanjo
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tsukano
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D007211:Indoles; D013141:Spiro Compounds; C487224:elacomine; C487225:isoelacomine; D010165:Palladium; D001729:Bismuth