Fungus reinforced sustainable gold nanoparticles: An efficient heterogeneous catalyst for reduction of nitro aliphatic, aromatic and heterocyclic scaffolds

Abstract

Heterogeneous catalyst is essential for an efficient and environmental friendly process development in chemical industries. As a green chemistry prospective, recovery and reusability of catalyst is in great demand for industrial processes. Herein this report, a robust protocol with novel catalyst has been developed for the selective reduction of nitro functionality on aliphatic, aromatic and heterocyclic scaffolds using sodium borohydride in water. Aspergillus trinidadensis (VM ST01′ OL587588) supported gold nano heterogeneous catalyst (AtGNHC) has efficiently and selectively reduced the nitro group in the presence of different other functional groups like olefins, esters, amide, nitriles, carboxylic and halides (-F, -Cl, -Br). The amino products with industrial importance for the preparation of pharmaceuticals, polymers and agrochemicals are obtained in good isolated yields (up to >95 %) under mild conditions. AtGNHC is lyophilized to make it as a robust free flowing powder, which can be used as regular chemicals. As a requirement of sustainable chemistry, the catalyst reusability has been also investigated and it has shown almost same efficiency all the time (10 cycles are performed). A storage stability of lyophilized AtGNHC has been also performed and it has shown excellent catalytic activity even after one year of storage at normal conditions. AtGNHC has demonstrated its efficacy in scale-up process (tried up to 5gm batch) also with same reactivity. Results presented and discussed in this report are clearly showing the potency of AtGNHC as a choice for chemical industries with commercial value.

Keywords

• Amino compound
• Heterogeneous catalysts
• Transfer hydrogenation
• Fungus support
• Gold nanoparticles