Ruthenium Complexes Bearing α‑Diimine Ligands and Their Catalytic Applications in N‑Alkylation of Amines, α‑Alkylation of Ketones, and β-Alkylation of Secondary Alcohols

New Ru(II) complexes encompassing α-diimine ligands
were
synthesized by reacting ruthenium precursors with α-diimine
hydrazones. The new ligands and Ru(II) complexes were analyzed by
analytical and various spectroscopic methods. The molecular structures
of L1 and complexes 1, 3, and 4 were determined by single-crystal XRD
studies. The results reveal a distorted octahedral geometry around
the Ru(II) ion for all complexes. Moreover, the new ruthenium complexes
show efficient catalytic activity toward the C–N and C–C
coupling reaction involving alcohols. Particularly, complex 3 demonstrates effective conversion in N-alkylation of aromatic
amines, α-alkylation of ketones, and β-alkylation of alcohols.

本研究通过钌前驱体与α-二亚胺腙（α-diimine hydrazones）反应，合成了一系列包含α-二亚胺配体（α-diimine ligands）的新型二价钌（Ru(II)）配合物。采用分析化学手段与多种光谱学方法，对所制备的新型配体及二价钌配合物进行了表征分析。通过单晶X射线衍射（single-crystal XRD）测试，解析了配体L1以及配合物1、3和4的分子晶体结构。结果显示，所有目标配合物中的二价钌离子均呈现扭曲八面体配位构型。此外，该系列新型钌配合物对以醇为底物的C-N键与C-C键偶联反应展现出高效的催化活性。尤为突出的是，配合物3在芳香胺的N-烷基化、酮的α-烷基化以及醇的β-烷基化反应中均表现出优异的底物转化率。