Gold nanoparticle supported on ionic liquid-modified graphene oxide as an efficient and recyclable catalyst for one-pot oxidative A³-coupling reaction of benzyl alcohols

Abstract

A novel gold nanoparticle supported on graphene oxide with ionic liquid framework was used as a highly active and recyclable catalyst for novel domino oxidative A3-coupling reaction.

Modified Nanocarbons for Catalysis

“…A methylimidazolium chloride‐based silane was grafted onto the surface of GO to obtain material 137 . The ion exchange with HAuCl 4 led to the formation of material 138 (Scheme ) . Despite GO was modified with AuCl 4 − ions, XPS analysis furnished evidence of the presence of metallic gold (Au 0 /Au 3+ ratio: 4 : 6) arising from reduction of Au 3+ species by GO support as previously reported .…”

A Review on Recent Advances in the Application of Nanocatalysts in A3 Coupling Reactions

“…For example, in 2014, Dabiri et al. reported preparation of novel recyclable catalyst through simple ion exchange and subsequent chemical reduction for the immobilization of AuCl 4 − on GO‐IL that provides the corresponding catalyst (Au@GO‐IL) . The synthesis of GO with ionic liquid framework (GO‐IL) is performed through a silylation modification procedure on GO.…”

“…It is important to stress that despite huge advancements of the reported works in the literature, another important challenges in the A 3 coupling reactions is nature of solvent and kind of the catalyst. A number of nanocatalysts, including copper, silver, gold, nickel, magnetic nanocatalysts and Co 3 O 4 , ZnS and nanopowder zinc titanate were successfully applied for A 3 coupling reactions with yields ranging from good to excellent in appropriate times in organic solvents or aqueous medium . The authors ascribed high catalytic activity of nanocatalysts to the particles size.…”

Caffeine gold complex supported on magnetic nanoparticles as a green and high turnover frequency catalyst for room temperature A3 coupling reaction in water

“…Despite the high efficiency of the reported catalysts, in many cases high catalyst loading and the expensive price of gold considerably limit the versatility of these catalytic systems. Along this line, recently, different heterogeneous gold as well as magnetic catalysts have been applied for the A 3 coupling reaction. Herein we report for the first time the use of caffeine as a naturally occurring and cheap compound for the modification of magnetic NPs and for the stabilization of gold metal.…”