Hydrolysis of 8-Quinolyl Phosphate Monoester: Kinetic and Theoretical Studies of the Effect of Lanthanide Ions

作者：Souza Bruno S; Brandao Tiago A S; Orth Elisa S; Roma Ana C; Longo Ricardo L; Bunton Clifford A; Nome Faruk^*

来源：Journal of Organic Chemistry, 2009, 74(3): 1042-1053.

DOI：10.1021/jo801870v

8-Quinolyl phosphate (8QP) in the presence of the trivalent lanthanide ions (Ln = La, Sm, Eu, Tb, and Er) forms a [Ln center dot 8QP]( ) complex where the lanthanide ion catalyzes hydrolysis of 8QP. In reactions with Tb(3 ) or Er(3 ), there is evidence of limited intervention by a second lanthanide ion. Rate constants are increased by more than 10(7)-fold, and kinetic data and B3LYP/ECP calculations indicate that the effects are largely driven by leaving group and metaphosphate ion stabilization. The lanthanides favor a single-step D(N)A(N) mechanism with a dissociative transition state, with limited nucleophilic assistance, consistent with the low hydroxide ion dependence and the small kinetic effect of Ln(3 ) radii.

• 出版日期2009-2-6