Carbonylative Suzuki‐Miyaura Cross‐Coupling Over Pd NPs/Rice‐Husk Carbon‐Silica Solid Catalyst: Effect Of 1,4‐Dioxane Solvent

Abstract

With the aim of investigating the role of solvent in directing the product selectivity in carbonylative Suzuki‐Miyaura cross‐coupling (CSMC), Rice‐Husk (RH) derived carbon‐silica supported palladium nanoparticle (PdNPs/C‐SiO2) catalysts were prepared and characterized by various techniques. The structural and textural properties of these catalysts have been determined by XRD, BET, SEM, TEM, FT‐IR and XPS. In CSMC over Pd NPs/C‐SiO2 catalysts solvents are playing a critical role in directing the product selectivity particularly with 1, 4‐dioxane solvent biaryl ketone alone formed from iodobenzene, carbon monoxide and phenylboronic acid, addressing the in‐situ formation of phenylboronate ester from 1, 4‐dioxane solvent and phenyl boronic acid and subsequent biaryl ketone formation with 100% selectivity and appealing catalytic activity ( Extreamly high TON= 3,61,650).

Biomass waste rice husk derived silica supported palladium nanoparticles: an efficient catalyst for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions

“…As shown in Fig. 2, the Pd 3d spectra of 1% PdNPs/RH-SiO 2 catalyst display two peaks, the binding energies centered at 343.2 and 337.8 eV are attributed to 3d 5/2 and 3d 3/2 of palladium in zero oxidation state, which is consistent with the reported values for palladium in zero-valent [60]. In the case of 1% PdNPs/FM-SiO 2 and 1% PdNPs/G-SiO 2 catalysts, the Pd 3d peaks are shifted to lower binding energies (342.9, 337.1 eV and 341, 336 eV).…”

“…RH-SiO 2 support was prepared according to the reported procedure with modifications and details are shown in Scheme 1 [57,60]. In a typical procedure, a required amount of raw rice husk was added to 0.1 M HCl solution and stirred at 100 °C for 6 h. Then, the mixture was cooled down to room temperature, and the solids were filtered and washed with distilled water to reach the pH ~ 7.…”

“…Since the high content of amorphous silica, rice husk is being considered as an excellent precursor for the preparation of nano and mesoporous silica materials [57][58][59]. Recently, rice husk derived carbon-supported catalysts have been developed and applied successfully for C-C coupling reactions [60,61]. Therefore, the preparation of rice husk derived amorphous SiO 2 supported Pd catalysts is considered to be a green and low-cost approach for C-C coupling reactions.…”

Agricultural waste biomass-assisted nanostructures: Synthesis and application

“…Burri and co-workers prepared PdNPs of 3.5-4.5 nm in size supported on high surface area nanoporous silicacarbon (PdNP@Si-C) by calcination of acid wash husk rice under inert atmosphere [28]. This catalyst was studied in the carbonylative Suzuki coupling reaction of various types of aryl iodides in 1,4-dioxane at 120°C under carbon monoxide atmosphere (Scheme 3).…”

Novel and efficient bridged bis(N‐heterocyclic carbene)palladium(II) catalysts for selective carbonylative Suzuki–Miyaura coupling reactions to biaryl ketones and biaryl diketones

“…This method is the palladium‐catalyzed Suzuki−Miyaura coupling reaction of aryl halides with aryl boronic acids in the presence of carbon monoxide (CO) as the carbonyl source 20,21 . Since 1993, many publications have reported using various palladium catalysts in carbonylative Suzuki−Miyaura coupling, but this method has some drawbacks, such as high catalyst loading, high CO pressure, long time, high temperature, and low selectivity control, and in addition most of these reactions need high loading of phosphine ligands even with aryl iodides 7,20,22–31 …”