title: Gold-Catalyzed [3+2]/Retro-[3+2]/[3+2] Cycloaddition Cascade Reaction of N-Alkoxyazomethine Ylides.
abstract: A novel cascade reaction has been developed for the synthesis of 2,6-methanopyrrolo[1,2-b]isoxazoles based on the gold-catalyzed generation of an N-allyloxyazomethine ylide. This reaction involves sequential [3+2]/retro-[3+2]/[3+2] cycloaddition reactions, thus providing facile access to fused and bridged heterocycles which would be otherwise difficult to prepare using existing synthetic methods. Notably, this reaction allows the efficient construction of three C-C bonds, one C-O bond, one C-N bond and one C-H bond, as well as the cleavage of one C-C bond, one C-O bond and one C-H bond in a single operation. The intermolecular cycloaddition of an N-allyloxyazomethine ylide and the subsequent application of the product to the synthesis of tropenol is also described.
authors.affiliation: Kobe Pharmaceutical University, 4-19-1 Motoyamakita, Higashinada, Kobe, 658-8558, Japan.
authors.forename: Shoichi
authors.identifier: 0000-0003-4870-7964
authors.initials: S
authors.lastname: Sugita
authors.affiliation: Kobe Pharmaceutical University, 4-19-1 Motoyamakita, Higashinada, Kobe, 658-8558, Japan.
authors.forename: Norihiko
authors.identifier: 0000-0003-2330-0201
authors.initials: N
authors.lastname: Takeda
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Norimitsu
authors.identifier: 0000-0001-7051-7599
authors.initials: N
authors.lastname: Tohnai
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
authors.forename: Mikiji
authors.identifier: 0000-0002-0170-737X
authors.initials: M
authors.lastname: Miyata
authors.affiliation: Kobe Pharmaceutical University, 4-19-1 Motoyamakita, Higashinada, Kobe, 658-8558, Japan.
authors.forename: Okiko
authors.identifier: 0000-0003-4247-1161
authors.initials: O
authors.lastname: Miyata
authors.affiliation: Kobe Pharmaceutical University, 4-19-1 Motoyamakita, Higashinada, Kobe, 658-8558, Japan.
authors.forename: Masafumi
authors.identifier: 0000-0002-8003-2971
authors.initials: M
authors.lastname: Ueda
keywords: azomethine ylides; cycloaddition; gold; heterocycles; synthetic methods