Solid‐state Suzuki–Miyaura cross‐coupling: A sustainable approach by DDIL‐stabilized magnetic separable and recyclable Pd nanoparticles with total solvent bypass

Abstract

A new method for the sustainable synthesis of various functionalized biaryls through the solid‐state Suzuki–Miyaura cross‐coupling reaction has been developed. This solid‐state protocol employs a palladium catalyst anchored on diazabicyclo[2.2.2]octane silica ferrite composite (Pd‐DDIL@Fe3O4‐SiO2). The catalyst has been fully characterized using multiple techniques such as FTIR, XRD, FESEM, EDS, elemental mapping, HR‐TEM, XPS, BET, TGA‐DTA, and VSM. The Pd‐DDIL@Fe3O4‐SiO2 catalyst has a surface area of 60.17 m2 g−1 and a magnetization saturation of 40.95 emu g−1. The TEM analysis revealed the rough spherical morphology of PdNPs having a particle size of 7 nm. The catalyst has excellent activity and selectivity towards the synthesis of both symmetrical and unsymmetrical biaryls under solid‐state, solvent‐free grinding conditions using a mortar and pestle. This method is eco‐friendly, as it is performed at room temperature without any solvents. The method employs the excellent yield of the products (90–96%) in a short reaction time (3–20 min). The desired products are isolated easily without any use of organic solvents. The catalyst can be easily separated using an external magnet and reused at least six times with an admirable change in yield. Additionally, the catalytic system has been shown to have a high TON and TOF, thus confirming its sustainability.