南方科技大学郑智平课题组报道了用于催化Knoevenagel缩合的中空异质金属团簇。相关论文于2024年11月12日发表在《德国应用化学》杂志上。

含镧系团簇是一种具有挑战性的合成材料，具有重要的化学和材料应用。

本文采用Ln³⁺（Gd³⁺或Eu³⁺）和Ni²⁺在亚氨基二乙酸酯（IDA）存在下，共水解得到两种同分异构的异质金属团簇：(NO₃)₁₂@[Ln₁₃₂Ni₇₈(OH)₂₉₂(IDA)₄₈(CH₃COO)₉₆(NO₃)₁₂(H2O)₇₈]Cl₄₄·xH₂O·yCH₃OH (IDA =亚氨基二乙酸酯；Ln = Gd 1, x = 110, y = 0; Ln = Eu 2, x = 95, y = 40)。

晶体学研究表明，每一种材料都具有截断的Ln₁₃₂Ni₇₈四面体核，其中的空隙为5.5直径；连接中心笼及其外部的，是表面装饰有[Gd(μ3-OH)₂Gd]双核单位的号角状通道。质谱分析表明，两种团簇在水溶液中保持结构完整性，低温电子显微镜提供了最令人信服的视觉证据，支持团簇的溶液稳定性。

根据实验和分子模拟结果，尺寸选择性Knoevenagel缩合被认为发生在通道中，在1的存在下实现。通过一锅三组分合成具有重要生物学和药学意义的4H-吡喃衍生物，进一步说明了1作为结构独特的分子反应器和可回收的多相催化剂的应用。

附：英文原文

Title: A Hollowed-Out Heterometallic Cluster for Catalytic Knoevenagel Condensation

Author: Wanmin Chen, Na Xu, Lei Qin, Yi-Fei Deng, Gui-Lin Zhuang, Zhe Zhang, Ting-Zheng Xie, Pingshan Wang, Zhiping Zheng

Issue&Volume: 2024-11-12

Abstract: Lanthanide-containing clusters are synthetically Lanthanide-containing clusters are synthetically challenging and with significant chemical and materials applications. Herein, two isostructural heterometallic clusters of the formula (NO3)12@[Ln132Ni78(OH)292(IDA)48(CH3COO)96(NO3)12(H2O)78]Cl44·xH2O·yCH3OH (IDA = iminodiacetate; Ln = Gd 1, x = 110, y = 0; Ln = Eu 2, x = 95, y = 40) were obtained via co-hydrolysis of Ln3+ (Gd3+ or Eu3+) and Ni2+ in the presence of iminodiacetate (IDA). Crystallographic studies show that each features a truncated tetrahedral core of Ln132Ni78 within which a void of 5.5 in diameter; connecting the central cage and its exterior are four trumpet-like passageways surface-decorated with dinuclear units of [Gd(μ3-OH)2Gd]. Mass spectroscopic analyses indicate that both clusters maintained their structural integrity in aqueous solution, with cryo-electron microscopy providing the most convincing visual evidence in support of the cluster's solution stability. Size-selective Knoevenagel condensation, believed to occur in the passageways on the basis of experimental and molecular modeling results, was achieved in the presence of 1. The application of 1 as a uniquely structured molecular reactor and a recyclable heterogeneous catalyst was further illustrated by the one-pot three-component synthesis of biologically and pharmaceutically significant 4H-pyran derivatives.

DOI: 10.1002/anie.202420770

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202420770