Combined CoNi2S4/LaCu0.5Fe0.5O3 Nanocatalyst for Efficient Synthesis of Propargylamines via Solvent-Free A3-Coupling Reactions

In this study, a novel nanocomposite catalyst consisting of spinel CoNi 2 S 4 nanoparticles supported on LaCu 0.5 Fe 0.5 O 3 perovskite was successfully synthesized and applied to the A 3 -coupling reaction for the efficient synthesis of propargylamines. Comprehensive structural, morphological, and surface characterizations (FT-IR, XRD, XPS, SEM, EDX, TEM, BET, AAS, and GC-MASS) confirmed the formation of a well-defined and stable redox-active composite enriched with oxygen vacancies and mixed-valence metal centers. These intrinsic features endowed the catalyst with remarkable activity, excellent selectivity, and outstanding stability under solvent-free conditions. Importantly, the catalyst maintained its efficiency over multiple reaction cycles without noticeable loss of performance. The synergistic interplay between the perovskite matrix and the spinel sulfide phase enhanced electron transport and increased the accessibility of active sites, thereby facilitating efficient C–C and C–N bond formation under mild conditions. Overall, this work highlights the potential of engineered perovskite–spinel nanocomposites as robust, sustainable, and highly efficient catalysts for modern organic transformations and green chemistry applications.