title: Asymmetric synthesis of spiropyrazolones through phosphine-catalyzed [4+1] annulation.
abstract: An enantioselective synthesis of spiropyrazolones from allenoate-derived MBH acetates and pyrazolones through a phosphine-mediated [4+1] annulation process has been developed. Spiropyrazolones were readily prepared in good chemical yields and good to high enantioselectivities. This is the first asymmetric example in which α-substituted allenoates were utilized as a C4 synthon for phosphine-catalyzed [4+1] annulation.
authors.affiliation: Zhejiang Provincial Key Laboratory for Chemical & Biochemical Processing Technology of Farm Products, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, No. 318 Liuhe Road, Hangzhou, 310023 (China); Department of Chemistry & Medicinal Chemistry Program, Life Sciences Institute, National University of Singapore (NUS), 3 Science Drive 3, Singapore 117543 (Singapore).
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Han
authors.forename: Weijun
authors.initials: W
authors.lastname: Yao
authors.forename: Tianli
authors.initials: T
authors.lastname: Wang
authors.forename: Yong Ren
authors.initials: YR
authors.lastname: Tan
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Yan
authors.forename: Jacek
authors.initials: J
authors.lastname: Kwiatkowski
authors.forename: Yixin
authors.initials: Y
authors.lastname: Lu
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D061565:Cycloaddition Reaction; D008968:Molecular Conformation; D010720:Phosphines / Q000737:chemistry*; D047069:Pyrazolones / Q000138:chemical synthesis / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D010720:Phosphines; D047069:Pyrazolones; D013141:Spiro Compounds; C044646:phosphine
keywords: [4+1] annulation; allenoates; chiral phosphines; spiro compounds; spiropyrazolones