Cu(ClO4)2诱导的N-苯基二吡啶甲基胺的邻位苯甲基化及其溴桥联铜配合物的形成

N-苯基二吡啶甲基胺和苯甲基溴在Cu(ClO4)2存在的条件下反应导致N-苯基二吡啶甲基胺的邻位苯甲基化和一个新的溴桥联的双核铜配合物的形成。实验结果显示阴离子显著影响反应的选择性,CuCl2和Cu(NO3)2不能提高N-苯基二吡啶甲基胺邻位苯甲基化的选择性。NMR和元素分析数据证实N-苯基二吡啶甲基胺邻位苯甲基化产物的形成。X-射线晶体结构数据表明溴桥联的双核铜配合物中铜原子被3个N原子,1个配位溴离子和1个μ2-桥联的溴结合形成扭曲的三角双锥的构型。研究结果表明Cu(ClO4)2可作为N-苯基二吡啶甲基胺邻位烷基化反应的催化剂。研究结果有助于设计新的选择性苯甲基化催化剂。

Cu(ClO4)2 Induced Ortho-Benzylation of N-Benzyl Di(pyridylmethyl)amine and the Formation ofμ2-Br-Bridged Copper(H) Complexes

The reaction of N-benzyl di(pyridylmethyl)amine (phdpa) and benzyl bromide in the presence of Cu(ClO4)2,leads to the ortho-benzylation of phdpa with the formation of μ2-Br-bridged copper(Ⅱ) complexes due to the coordination of bromine atoms to the center copper atom in phdpa-Cu(ClO4)2.CuCl2 and Cu(NO3)2 could not increase the selectivity for intramolecular ortho-benzylation of phdpa indicating that anions have great effect on the reaction.The ortho-benzylation product N-(2-benzyl)benzyl]-di(picolyl)amine perchlorate was confirmed by NMR data and elemental analysis.X-ray crystal structure of μ2-Br-bridged dinuclear copper(Ⅱ) complex shows that two copper(Ⅱ) ions are coordinated by three N atoms,one coordinated bromine atom and a bridged bromine atom resulting in a distorted trigonal bipyramidal geometry.This experimental result indicates that Cu (ClO4)2 could induce selectively the intramolecular ortho-benzylation of phdpa.This experimental result is meaningful to find selective benzylation catalysts.CCDC:759823.