Synthesis, characterization, and the role of counterion in cyclopropanation of styrene catalyzed by [CuI(2,2′-bpy)(π-CH2CHC6H5)][A] complexes
作者:Carolynne Ricardo、Tomislav Pintauer
DOI:10.1016/j.jorganchem.2007.07.045
日期:2007.11
Copper(I)/2,2'-bipyridine complexes, [Cu-I(bpy)(pi-CH2CHC6H5)][A] (A = CF3SO3- (1), PF6- (2)) have been synthesized and characterized. The equilibrium constants for the coordination of styrene to [Cu-I(bpy)](+) cations at 300 K were determined to be 4.3 x 10(3) (1), 4.4 x 10(3) (2) and 3.8 x 10(3) M-1 (A = ClO4-, 3). These data suggested that the axial coordination of the counterion in these complexes observed in the solid state (2.4297(11) angstrom 1, 2.9846(12) angstrom 2, and 2.591(4) A 3) did not significantly affect the binding constant of styrene to [Cu-I(bpy)](+) cations in solution. In cyclopropanation reactions catalyzed by 1-3, similar product distribution was obtained. The rate of decomposition of EDA in the presence of styrene at room temperature catalyzed by 3 (k(obs) = (7.7 +/- 0.32) x 10(-3) min(-1)) was slower than the rate observed for 1 (K-obs = (1.4 +/- 0.041) x 10(-2) min(-1)) or 2 (k(obs) = (1.0 +/- 0.025) x 10(-2) min(-1)). (c) 2007 Elsevier B.v. All rights reserved.