Remodeling of N‑Heterocyclic Iminato Ligand Frameworks for the Facile Synthesis of Isoureas from Alcohols and Carbodiimides Promoted by Organoactinide (Th, U) Complexes

A new class of actinide complexes [(L)­An­(N­{SiMe3}2)3] (An = Th or U) (Th1–Th3 and U1–U3) supported by highly nucleophilic seven-membered N-heterocyclic iminato ligands were synthesized and fully characterized by single-crystal X-ray diffraction. These complexes were successfully exploited as powerful catalysts for the addition of alcohols to carbodiimides to yield the corresponding desirable isourea products at room temperature with short reaction times and excellent yields. Thorough stoichiometric, thermodynamic, and kinetic studies were carried out, allowing us to propose a plausible mechanism for the catalytic reaction.

本研究合成了一种新型的由高亲核性七元氮杂环亚氨基配体配位稳定的锕系配合物（actinide complexes）[(L)­An­(N­{SiMe3}2)3]（其中An代表钍（Th）或铀（U），对应配合物编号为Th1–Th3与U1–U3），并通过单晶X射线衍射（single-crystal X-ray diffraction）对其进行了全面表征。该系列配合物可作为高效催化剂，用于催化醇与碳二亚胺（carbodiimides）的加成反应，能够在室温下以较短的反应时间和优异的收率得到相应的目标异脲（isourea）产物。通过开展全面的化学计量学、热力学及动力学研究，我们提出了该催化反应合理的反应机理。