Transformation of One-Dimensional Achiral Structure to Three-Dimensional Chiral Structure: Mechanistic Study and Catalytic Activities of Chiral Structure

We have isolated two copper-based
coordination polymers through solvent diffusion and solvothermal methods
using copper salt, furan dicarboxylic acid (FDC), 4,4′-bipyridine
(bpy) in MeOH/​ethylene glycol, and water solvents. Compound 1 is adopting P21/c space group and adopts a one-dimensional wirelike structure with
a free carboxylate anion. Compound 2 crystallizes in
chiral space group P65. This is a three-dimensional
structure with helical chains. This helicity might be the reason for
chiral generation and symmetry breaking. We have converted compound 1 to compound 2 using grinding, followed by a
solvothermal method. The circular dichroism data of 2 showed that it is an enantioenriched compound. We have shown that
compound 2 is a very good catalyst for chemo- and regioselective
enamination reaction and for azide–alkyne Huisgen cycloaddition,
respectively.

本研究采用溶剂扩散法与溶剂热法，以铜盐、呋喃二羧酸（furan dicarboxylic acid, FDC）、4,4'-联吡啶（4,4'-bipyridine, bpy）为构筑单元，在甲醇（MeOH）/乙二醇与水的混合溶剂中，成功制备并分离得到两种铜基配位聚合物。化合物1结晶于P21/c空间群，呈现出带有游离羧酸根阴离子的一维线状结构。化合物2结晶于手性空间群P65，具有螺旋链的三维结构。该螺旋性特征可能是手性产生与对称性破缺的成因。本研究通过研磨结合溶剂热法，实现了化合物1向化合物2的转化。对化合物2的圆二色性（circular dichroism）测试结果显示，其为对映体富集的手性化合物。实验证实，化合物2分别是化学选择性与区域选择性胺化反应、叠氮-炔烃Huisgen环加成反应的优良催化剂。