Sustainable synthesis of drug intermediates via simultaneous utilization of carbon monoxide and ammonia over Pd@La-MOF

Abstract

Mitigation of carbon monoxide and ammonia to valuable primary aromatic amides is an imperative approach to control the environmentally harmful emissions thereby infusing towards sustainability. Designing of nanostructured catalyst for direct access to the synthetically valuable primary aromatic and heteroaromatic amides via carbonylative amination of aryl halides is always demanding since nano materials can bridge the gap between homogeneous and heterogeneous catalysis thus preserving the desirable attributes of both the systems towards sustainable catalysis. Herein, microwave assisted fabrication of highly uniform Pd NPs (3,4 nm) over La-MOFs has been performed and utilized efficiently for ligand free carbonylative amination of aryl iodides with carbon monoxide and ammonia. Moderate to high yields of benzamide derivatives, salicylamide, a drug having analgesic and antipyretic properties were achieved. The unsaturated metal sites in the MOF via synergistic mode of σ and π bonding binds with CO, which significantly enhances the catalytic activity of MOF-composite unlike other supported Pd NPs. DFT confirms the growth of pristine Pd13 cluster within the framework, as active metal center for the carbonylative amination.