Applied Chemistry Today

Applied Chemistry Today

Biomass-Derived Cu-CuO-Cu2O/Graphene-Like Carbon as a Microwave-Responsive Catalyst for A3 Coupling

Document Type : Original Article

Authors
Department of Chemistry, Semnan University, P.O. Box 35131-19111, Semnan, Iran
Abstract
This study introduces a novel Cu-CuO-Cu2O/GLC nanocomposite catalyst derived from basil seed hydrogel for efficient propargylamine synthesis via A3 coupling reactions. The catalyst was prepared through Cu2+ ion immobilization in basil seed hydrogel, followed by controlled calcination, resulting in a hierarchical porous structure with synergistic copper species supported on biomass-derived graphene-like carbon. Under optimized solvent-free conditions, the catalyst demonstrated exceptional performance in the three-component coupling of aldehydes, amines, and terminal alkynes. Notably, microwave irradiation dramatically enhanced catalytic efficiency, reducing reaction times from 2 hours to 30 minutes while increasing yields from 90% to 98%. The catalyst exhibited a distinct 4.35-fold increase in turnover frequency under microwave conditions (5.44×10-5 mol g-1 s-1) compared to conventional heating (1.25×10-5 mol g-1 s-1). Hammett correlation analysis (ρ = 0.3) confirmed that electron-withdrawing substituents accelerate the reaction by enhancing carbonyl electrophilicity. The catalyst maintained effective activity through five consecutive cycles with minimal deactivation and demonstrated actual heterogeneous behavior. Comprehensive economic and green chemistry evaluations revealed significant advantages over conventional catalysts, including a 5-15 fold reduction in cost per reaction (0.20−0.35 vs. 1.0-4.5) and significant environmental metrics with an E-factor of 2.5-4 compared to 10-45 for other systems. This biomass-derived catalyst represents an economically viable and environmentally sustainable approach to valuable propargylamine scaffolds.
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Articles in Press, Accepted Manuscript
Available Online from 19 September 2026