Iron N-Doped Carbon Nanoarchitectonics for C─H Bond Activation of Methylarenes and Esterification Reactions

Nowadays, selective oxidation of sp³ C-H bond in methylarene to benzaldehyde under eco-friendly conditions is a promising way to produce aldehyde derivatives. In this work, scalable iron nanoparticles adorned on surface engineered nitrogen-doped carbon (Fe_NP@NC-BA) fabricated via wet chemistry followed by high-temperature pyrolysis. It is observed that nitrogen-coordinated Fe nanoparticles play a crucial role as active sites in facilitating both the toluene oxidation and esterification reaction due to its nitrogen-rich Fe NPs contain and low C/N ratio in Fe_NP@NC-BA catalyst. The Fe_NP@NC-BA catalyst and N-hydroxyphthalimide cooperatively converted methylarenes to corresponding aryl aldehydes with 99% conversion and selectivity, without over-oxidation of benzaldehyde to benzoic acid at room temperature. Further, EPR analysis is used to probe the free radical pathway followed in C-H activation. Additionally, Fe_NP@NC-BA catalyst employed for microwave-assisted esterification of acids with alcohols leads to 99% conversion and selectivity. The compatibility of Fe_NP@NC-BA nanoarchitectonics employed for the highly efficient synthesis of selective 24 benzaldehyde derivatives and 42 ester products. Furthermore, a gram-scale catalyst reusability study proved the wide applicability of Fe_NP@NC-BA catalyst. Thus, Fe nanoparticles decorated with N-doped carbon catalysts provide a durable, easily recoverable, and environmentally friendly metal-based catalyst for oxidation and esterification reactions.