title: In Situ Generated Zinc(II) Catalyst for Incorporation of CO2into 2-Oxazolidinones with Propargylic Amines at Atmospheric Pressure.
abstract: Incorporation of CO2into heterocyclic compounds (i.e., 2-oxazolidinones) under mild conditions, especially at atmospheric pressure still remains challenging. The mononuclear ZnIIcomplex ZnCl2(TBD)2, where TBD=1,5,7-triazabicyclo[4.4.0]dec-5-ene, in this study was demonstrated as a robust catalyst for the carboxylative cyclization of propargylic amines with CO2to exclusively afford various 2-oxazolidinones in excellent yields. Notably, the ZnIIcatalytic species is readily generated in situ from ZnCl2and TBD without pre-preparation and further isolation. Such a CO2fixation protocol could proceed smoothly under atmospheric pressure at mild temperature in an atom economic and environmentally benign manner.13C NMR and control experiments were performed to explore the possible interaction between ZnIIand the carbon-carbon triple bond of propargylic amine. The dual catalytic role of the Zn catalyst to enhance O-nucleophilicity of the carbamate anion intermediate and activate the carbon-carbon triple bond is proposed based on mechanistic investigations.
authors.affiliation: State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P R China.
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P R China.
authors.forename: Mei-Yan
authors.initials: MY
authors.lastname: Wang
authors.affiliation: State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P R China.
authors.forename: Si-Yuan
authors.initials: SY
authors.lastname: Wang
authors.affiliation: State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P R China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P R China.|Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin, 300071, P R China.
authors.forename: Liang-Nian
authors.identifier: 0000-0002-6067-5937
authors.initials: LN
authors.lastname: He
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D001274:Atmospheric Pressure; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D023303:Oxazolidinones / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D000480:Alkynes; D000588:Amines; D023303:Oxazolidinones; D002245:Carbon Dioxide; D015032:Zinc
keywords: carbon dioxide; carboxylative cyclization; catalysis; dual activation; zinc