Integration of Pd and Cu on polymer: a powerful bimetallic heterogeneous catalyst for sequential synthesis of quinoxalines

Article abstract of DOI:10.1007/s11164-019-03918-w

Pd²⁺/Cu²⁺ bimetallic catalysts immobilized on ethylenediamine-functionalized poly(vinyl chloride) (Pd^II/Cu^II@EDA-PVC) were developed by combining two metallic catalysts that complement rather than inhibit one another. The synthesized Pd^II/Cu^II@EDA-PVC were screened for their catalytic activity and found to be excellent in the one-pot sequential synthesis of quinoxalines from 1,2-diphenylacetylenes and o-phenylenediamines. Both Pd²⁺ and Cu²⁺ are indispensable and play crucial roles in this transformation. This one-pot sequential reaction proceeds well and tolerates various available substrates to form the desired product in excellent yield. A plausible mechanism was proposed for this conversion.