title: Highly regioselective [3 + 2] annulation of azomethine imines with 1-alkynyl Fischer carbene complexes to functionalized N,N-bicyclic pyrazolidin-3-ones.
abstract: The highly regioselective [3 + 2] cycloaddition of azomethine imines to 1-alkynyl Fischer carbene complexes has been successfully realized under mild conditions. Oxidative demetalation of the newly formed pyrazolo-pyrazolone carbene complexes with pyridine-N-oxide or ceric ammonium nitrate efficiently afforded pyrazolo-pyrazolone derivatives as well as cycloprop-2-enone and trisubstituted 1H-pyrazoles in some cases, providing a novel route to versatile functionalized N,N-bicyclic pyrazolidin-3-ones.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian, Liaoning 116023, P. R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Luo
authors.forename: Zhaoyan
authors.initials: Z
authors.lastname: Zheng
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D003500:Cyclization; D007097:Imines / Q000138:chemical synthesis*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry*; D013237:Stereoisomerism; D013882:Thiosemicarbazones / Q000737:chemistry*
chemical_list: D000480:Alkynes; D001391:Azo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007097:Imines; D011720:Pyrazoles; D013882:Thiosemicarbazones; C512188:azomethine; C030011:carbene; C031280:pyrazole; D008697:Methane