title: One-Component Aluminum(heteroscorpionate) Catalysts for the Formation of Cyclic Carbonates from Epoxides and Carbon Dioxide.
abstract: New neutral and zwitterionic chiral NNO-donor scorpionate ligands 1 and 2 were designed to obtain new mononuclear and dinuclear NNO-heteroscorpionate aluminum complexes. Reaction of 1 with [AlR3] (R=Me, Et) in a 1:1 or 1:2 molar ratio afforded the neutral mononuclear alkyl complexes [AlR2(κ2-bpzappe)] {R=Me (3), Et (4); bpzappeH=2,2-bis(3,5-dimethylpyrazol-1-yl)-1-[4-(dimethylamino)phenyl]-1-phenylethanol} and bimetallic complexes [{AlR2(κ2-bpzappe)}(μ-O){AlR3}] [R=Me (5), Et (6)]. By reaction of complexes 3-6 with PhCH2Br, mononuclear and dinuclear cationic aluminum complexes [AlR2(κ2-bbpzappe)]Br {R=Me (7), Et (8); bbpzappeH=N-benzyl-4-[2,2-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1-hydroxy-1-phenylethyl]-N,N-dimethylbenzenaminium bromide} and [{AlR2(κ2-bbpzappe)}(μ-O){AlR3}]Br [R=Me (9), Et (10)] were synthesized. Both neutral aluminum complexes in the presence of Bu4NBr and cationic aluminum complexes were investigated as catalysts for cyclic carbonate formation from epoxides and carbon dioxide. Amongst them, complex 10 was found to be an efficient one-component catalyst for the synthesis of cyclic carbonates from both monosubstituted and internal epoxides and was shown to have broad substrate scope.
authors.affiliation: Departamento de Química Inorgánica, Orgánica y Bioquímica, and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Campus Universitario, 13071-, Ciudad Real, Spain.|Green Chemistry Centre of Excellence, Department of Chemistry, The University of York, York, YO10 5DD, UK.
authors.forename: Javier
authors.identifier: 0000-0002-1538-0689
authors.initials: J
authors.lastname: Martínez
authors.affiliation: Departamento de Química Inorgánica, Orgánica y Bioquímica, and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Campus Universitario, 13071-, Ciudad Real, Spain.
authors.forename: José A
authors.identifier: 0000-0002-5029-0507
authors.initials: JA
authors.lastname: Castro-Osma
authors.affiliation: Departamento de Química Inorgánica, Orgánica y Bioquímica, and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Campus Universitario, 13071-, Ciudad Real, Spain.
authors.forename: Carlos
authors.identifier: 0000-0002-7588-0781
authors.initials: C
authors.lastname: Alonso-Moreno
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, Avda. de Fuentenueva s/n, 18071-, Granada, Spain.
authors.forename: Antonio
authors.identifier: 0000-0003-3198-5378
authors.initials: A
authors.lastname: Rodríguez-Diéguez
authors.affiliation: Green Chemistry Centre of Excellence, Department of Chemistry, The University of York, York, YO10 5DD, UK.
authors.forename: Michael
authors.identifier: 0000-0002-6668-5503
authors.initials: M
authors.lastname: North
authors.affiliation: Departamento de Química Inorgánica, Orgánica y Bioquímica, and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Campus Universitario, 13071-, Ciudad Real, Spain.
authors.forename: Antonio
authors.identifier: 0000-0001-7230-6437
authors.initials: A
authors.lastname: Otero
authors.affiliation: Departamento de Química Inorgánica, Orgánica y Bioquímica, and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Campus Universitario, 13071-, Ciudad Real, Spain.
authors.forename: Agustín
authors.identifier: 0000-0002-2069-7453
authors.initials: A
authors.lastname: Lara-Sánchez
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002254:Carbonates / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D004852:Epoxy Compounds / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D002254:Carbonates; D004852:Epoxy Compounds; D006843:Hydrocarbons, Chlorinated; D002245:Carbon Dioxide; D000535:Aluminum
keywords: aluminum; carbon dioxide fixation; cyclic carbonates; epoxides; sustainable chemistry