title: Platinum catalyzed 7-endo cyclization of internal alkynyl amides and its application to synthesis of the caprazamycin core.
abstract: The scope and limitations of the platinum catalyzed 7-endo cyclization of internal alkynyl amides were investigated. Substitution of the alkyne with an aryl group gave better results, presumably because it stabilized the transition state. Applying the reaction to a secondary amide, the caprazamycin core was successfully synthesized from commercially available material in eight steps.
authors.affiliation: takemoto@pharm.kyoto-u.ac.jp
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tsukano
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Yokouchi
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Girard
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kuribayashi
authors.forename: Shota
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Taro
authors.initials: T
authors.lastname: Enomoto
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D003500:Cyclization; D010984:Platinum / Q000737:chemistry*
chemical_list: D000480:Alkynes; D000577:Amides; D001381:Azepines; D010984:Platinum