Synthesis and Structural Diversity of Heterobimetallic Lanthanide–Potassium Complexes and Catalytic Activity for Amidation of Aldehydes with Amines

Abstract

Four heterobimetallic lanthanide–potassium complexes stabilized by the carbon-bridged bis(phenolate) ligand MBMP2– (MBMP = 2,2′-methylene bis(6-tert-butyl-4-methylphenolate)), [{(MBMP)2La(THF)2}2K][K(THF)6] (1), [(MBMP)Nd(μ-MBMP)K(THF)]2 (2), [(THF)2Sm(MBMP)2K(THF)2] (3), and [(THF)2Yb(MBMP)2K(THF)3] (4), were synthesized, and their structural features were provided. It was found that the ionic radii of lanthanide metals have a profound effect on the structures of the heterobimetallic complexes. Complexes 1 to 4 are efficient catalysts for amidation reactions of aldehydes with amines to produce amides in good to excellent yields under mild conditions.