Ag, Au and ZrO₂@reduced graphene oxide nanocomposites; Pd free catalysis of suzuki-miyaura coupling reactions

Abstract

Suzuki coupling is a widely used, well-studied and versatile method in synthetic chemistry for development of C–C bonds where palladium-based catalysts have been used extensively in the reaction to date. We report a Suzuki-cross-coupling reaction for C–C bonds formation between aryl halides and phenylboronic acid by using Metal/metal oxide@Reduced graphene oxide nanocomposites being efficient, simple and cost-effective. In this work, plant mediated synthesis of silver, gold and zirconia nanoparticles doped Reduced Graphene Oxide nanocomposites is reported where 30 mg of each of the catalysts resulted in C-C bond formation achieving percentage yield comparable to palladium-based catalyst used as standard in series of reactions, attaining highest yield with silver based catalyst. The catalysts demonstrated high catalytic activity over four cycles of recycling with no loss. Bromoaryl and phenylboronic acid are coupled together by the increased surface area of the reduced graphene oxide substrate, which also exhibits enhanced reactivity toward other chemical reactions. XRD, FTIR and UV-VIS analyses were used to describe the synthesized catalyst. Using the devised technique, various substituted aryl halides have been used successfully with modest to high yields of the desired biphenyls.

Recent Progress in the Application of Palladium Nanoparticles: A Review

“…However, Pd catalysts have encountered some obstacles, such as low efficiency in separation limit, metal leaching, and insufficient selectivity. In this regard, effort has been dedicated to modify Pd-based catalysts to overcome obstacles caused by synthesis of Pd catalysts on the nanoscale and immobilizing them on a solid surface [179]. Baran and co-worker synthesized a Pd NPs@Fe 3 O 4 /CS-AG catalyst and tested its performance in Suzuki-Miyaura reactions: that is, the reaction of phenylboronic acid with 4-iodoanisole under solvent-free and microwave irradiation.…”