Covalently anchored carboxylic acid on uniform spherical silica nanoparticles with narrow slit like mesopores for the synthesis of pyrroloacridinones: CuI-catalyzed further C(sp3)–H oxyfunctionalization for CO formation

Abstract

A new organic–inorganic hybrid catalyst (SMSNP-CA) was prepared by post synthesis grafting of –COOH functionalized organosilane on uniform spherical silica nanoparticles of 600 nm size with narrow slit like mesopores by using surface hydroxyl groups as anchor points. It was characterized by N₂ adsorption analysis, HRTEM, CHN analysis, ¹³C CP MAS, ²⁹Si MAS NMR and FTIR spectroscopy. The nanosilica particles possess unique morphological features. The broad applicability of SMSNP-CA was probed through a library synthesis of highly decorated pyrroloacridinone derivatives in the eco-friendly solvent ethanol. CuI-catalyzed further C (sp³)–H oxyfunctionalization leading to CO formation was carried out using O₂ as an environmentally benign and ideal oxidant since water is the only byproduct in these reactions.