Hierarchically Porous Mixed Oxide Sheetlike Copper-Aluminum Nanocatalyzed Synthesis of 2-Alkynyl Pyrrolidines/Piperidines and Their Ideal Green Chemistry Metrics

摘要

Design and development of selective and efficient catalysts involving abundantly available transition metal-based nanoparticles for multicomponent reaction in industry and academia have gained much attention in recent years. An efficient catalytic process not only reduces the manufacturing cost but also minimizes the waste disposal. Herein, we report the application of facile fabricated reusable calcinated copper-aluminum mixed oxide nanocomposites (CuAl-MO NCs) for highly efficient and selective one-pot green synthesis of substituted pyrrolidines/piperidines via KA(2) coupling reaction of a ketone, amine, and alkyne. The prepared material was well-characterized by HR-XRD, SEM, HR-TEM, EDX, ICP-OES/MS, BET, and XPS analyses, revealing highly dispersed porous sheetlike CuAL-MO NCs. The prepared CuAl-MO nanomaterial substantially boosted the catalytic efficiency by demonstrating high stability and easy retrievability of catalyst for successive reuses without significant loss in both activity and selectivity. The present methodology is facile, follows green principles, and showed ideal values of green chemistry metrics such as high atom economy (AE), reaction mass efficiency (RME), low E-factor, carbon efficiency (CE), and process mass intensity (PMI).