Ru (III) Schiff‐base complex anchored on nanosilica as an efficient and retrievable catalyst for hydration of nitriles

Abstract

Transition metal catalyzed hydration of nitriles is an attractive methodology for amide synthesis, and hence recently attracted wide attention. It is one of the significant organic transformations as amides play a vital role in biological, pharmaceutical and industrial applications. In this work, we report the synthesis of a new solid supported Ru (III) Schiff base complex, Ru@imine-nanoSiO 2 immobilized on nanosilica obtained from rice husk. The complex was characterized by FTIR, powder X-ray diffraction, BET surface area measurement, UV-vis, SEM-EDX, TEM, ESR, X-ray photoelectron spectroscopy and ICP-AES analysis. Using Ru@imine-nanoSiO 2 as the catalyst, the hydration of nitriles in i-PrOH at 40°C was studied which resulted in good isolated yields (60-99%). The catalyst can be recycled and reused up to 5 th cycle without any loss in activity. The products were characterized by FTIR, GC-MS and 1 H-NMR spectroscopy and compared with authentic samples.

Green synthesis of graphene oxide (GO)-anchored Pd/Cu bimetallic nanoparticles usingOcimum sanctumas bio-reductant: an efficient heterogeneous catalyst for the Sonogashira cross-coupling reaction

“…Contrastingly, there is no report available till date for the synthesis of bio-reduced graphene oxide supported bimetallic Pd/Cu nanocomposite and investigation of its heterogeneous catalytic potentiality in Sonogashira cross-coupling reaction in ethanol. From this point of view and in continuation of our previous works as well, 33,[45][46][47][48][49] here we report the synthesis and characterization of ligand-free, Pd-Cu bimetallic nanoparticles supported on graphene oxide by bio reduction method and its application in Sonogashira cross-coupling reaction.…”

Functionalized Silicas for Metal‐Free and Metal‐Based Catalytic Applications: A Review in Perspective of Green Chemistry

“…To synthesize Schiff base FSs with multiple functional groups from amine FSs, salicylaldehyde is very much intrigued due to its hydroxyl group located in the ortho position to carbonyl group . Apart from salicylaldehyde, isatin, 2‐pyridine carboxaldehyde, 4‐formylbenzoic acid, vanillin, acetyl acetonate and 3‐pyridine carboxaldehyde are the recently used carbonyl compounds during the synthesis of Schiff base FSs of multiple functional groups . T. Das et al.…”

“…According to the recent reports, the reaction schemes for the different coupling reactions, where either palladium(0) or palladium(II) immobilized on FS are utilized as the catalysts, are shown in Scheme . Palladium(0) NPs immobilized on different FSs have been recently employed as the catalysts for C−C coupling reactions such as Suzuki‐Miyaura, Heck‐Mirosoki and Stille coupling . In spite of displaying very good catalytic activity, these palladium(0)‐FS catalysts demonstrate excellent reusability because the leaching of palladium(0) active sites is greatly inhibited which befalls through the strong chemical interaction between palladium(0) and FSs.…”

“…While zirconyl Schiff base immobilized on amine FS is utilized for the conversion of fructose to 5‐hydrocymethylfurfural, ytterbium(III) anchored on thiol FS is used for the selective conversion of glucose/cellulose to lactic acid . Different metal ions/metal NPs that immobilized on various FSs such as ruthenium(III) on imine FS, palladium(II) on thiol FS, platinum(IV) on carboxylate FS, palladium(II) on pincer ligand FS, cobalt(II) on IL FS, copper(II) on imine FS, copper(II) on melamine FS, gold(I) on NHC FS and RuPd(0) on amine FS have shown the catalytic efficacy in the hydration of nitriles, cyanation of phenyl rings, hydrosilylation, α ‐arylation, acylation of aryl halides FS, oxidative condensation benzyl alcohol and amines, N‐formylation of amines, alkyne functionalization and ether bond cleavage (diphenylether), respectively.…”

Nickel(II) Schiff base complex supported on nano‐titanium dioxide: A novel straightforward route for preparation of supported Schiff base complexes applying 2,4‐toluenediisocyanate

“…[8] So, for improving the efficiency of their catalytic activity and ease of separation from reaction media, scientists have tried to convert them into heterogeneous systems in various ways. In this light, several methods can be used, such as: (1) linking onto metal oxides such as silica, Fe 3 O 4 and so on, [9][10][11] (2) immobilizing on organic supports like graphene oxide [12,13] and carbon nanotubes, [14] (3) copolymerizing and incorporating into an organic polymer like chitosan or porous polydivinylbenzene [15][16][17][18][19] and (4) encapsulating in various zeolites. [20][21][22] Organosulfur compounds such as sulfoxides and sulfones are very important compounds in organic chemistry.…”