[Zn2L(µ-OH)(OH)]2+ dominate. Complex 1 is a catalyst for the hydrolysis of the activated carboxy ester p-nitrophenyl acetate, with no loss of activity for at least 2.7 catalytic cycles. The second-order rate constant for cleavage of p-nitrophenyl acetate by 1 at 20 °C and pH 8.65 is (6.2 ± 0.6)× 10–3 dm3 mol–1 s–1. The pH dependence of the hydrolysis rate suggests that [Zn2L(µ-OH)(OH)]2+ is the catalytically
Catalytic Transesterification of Dialkyl Phosphates by a Bioinspired Dicopper(II) Macrocyclic Complex
作者:Malgorzata Jagoda、Sabine Warzeska、Hans Pritzkow、Hubert Wadepohl、Petra Imhof、Jeremy C. Smith、Roland Krämer
DOI:10.1021/ja051357b
日期:2005.11.1
activation of the substrate, combined with leaving group stabilization, has been proposed. Inspired by the active site structure of this enzyme, we have designed as a synthetic phosphoryl transfer catalyst the dicopper(II) macrocycliccomplex LCu(2). Crystal structures of complexes [(L)Cu(2)(mu-NO(3))(NO(3))](NO(3))(2) (1), [(L)Cu(2)(mu-CO(3))(CH(3)OH)](BF(4))(2) (2), and [(L)Cu(2)(mu-O(2)P(OCH(3))
对于许多磷酸转移酶,包括 DNA 聚合酶 I 的核酸外切酶亚基,已经提出了一种机制,涉及两种金属离子和底物的双路易斯酸活化,并结合离去基团的稳定性。受该酶活性位点结构的启发,我们设计了双铜 (II) 大环复合物 LCu(2) 作为合成磷酰基转移催化剂。配合物的晶体结构 [(L)Cu(2)(mu-NO(3))(NO(3))](NO(3))(2) (1), [(L)Cu(2)(mu -CO(3))(CH(3)OH)](BF(4))(2) (2) 和 [(L)Cu(2)(mu-O(2)P(OCH(3)) (2))(NO(3))](NO(3))(2) (3) 说明了含氧阴离子与二铜 (II) 位点相互作用的各种可能性。1 在 55 摄氏度下有效促进磷酸二甲酯 (DMP) 在 CD(3)OD 中的酯交换,k(cat) = 2 x 10(-)(4) s(-)(1)。1 是唯一可用的催化剂,可用于高度惰