title: CO2 reduction via aluminum complexes of ammonia boranes.
abstract: Reactions of amine-boranes NH3BH3, Me2NHBH3, or Me3NBH3 with AlX3 (X = Cl, Br, I, C6F5) have been examined. The species AlBr3·H3BNMe3 2, Al(C6F5)3·H3BNMe3 3, Al(C6F5)3·H3BNHMe2 4 and Al(C6F5)3·H3BNH3 5 have been prepared and isolated. The analogous reaction of B(C6F5)3 and H3BNMe3 results in C6F5-transfer and the formation of (C6F5)BH2·NMe3 6. While the adduct 6 was unreactive to CO2, species 3 reacts with CO2 to give the formate linked Al(C6F5)3(HCO2)H2BNMe38. The species R3PC(OAl(C6F5)3)2 (R = o-tol (1'-C6F5), R = Mes (1-C6F5)) were prepared, and 1'-C6F5 was shown to react with amine-boranes to effect the reduction of this bound-CO2 to formate and methoxide-derivatives, proceeding through intermediates including 8 and [(Me3NBH2)2(μ-H)][(HCO2)(Al(C6F5)3)2] 9. The salt [tBu3PH][(HCO2)(Al(C6F5)3)2] 10 was prepared independently.
authors: Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario M5S 3H6.
authors: Gabriel
authors: G
authors: Ménard
authors: Douglas W
authors: DW
authors: Stephan
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D000641:Ammonia / Q000737:chemistry*; D001880:Boranes / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D058116:Lewis Acids / Q000737:chemistry; D008968:Molecular Conformation; D010084:Oxidation-Reduction
chemical_list: D001880:Boranes; D056831:Coordination Complexes; D058116:Lewis Acids; D002245:Carbon Dioxide; D000641:Ammonia; D000535:Aluminum