Water-Dispersible Pd–N-Heterocyclic Carbene Complex Immobilized on Magnetic Nanoparticles as a New Heterogeneous Catalyst for Fluoride-Free Hiyama, Suzuki–Miyaura and Cyanation Reactions in Aqueous Media

Abstract

Pd-N-heterocyclic carbene complex immobilized on magnetic nanoparticles is synthesized and characterized by different techniques such as FT-IR, XPS, TEM, EDX, FESEM, VSM, TGA and ICP. The synthesized catalyst was used as a new water dispersible heterogeneous catalyst in the fluoride-free Hiyama, Suzuki and cyanation reactions in pure water. By this method, different types of biaryls and aryl nitriles were synthesized in good to high yields by the reaction of a variety of aryl iodides, bromides and chlorides with triethoxyphenylsilane, phenylboronic acid and K 4 [Fe(CN) 6 ]•3H 2 O, respectively. The presence of sulfonates as hydrophilic groups on the surface of the catalyst offers a highly water dispersible, active and yet magnetically recoverable Pd catalyst. The possibility to perform the reaction in water as a green medium, easy catalyst recovery and reuse by successive extraction and final magnetic separation, and the absence of any additives or co-solvents make this method as an eco-friendly and economical protocol for the synthesis of biaryl derivatives and aryl nitriles.

Magnetic Pd–Fe nanoparticles for sustainable Suzuki–Miyaura cross-coupling reactions

“…8,9 Leveraging these benefits, the integration of magnetic supports such as Fe 3 O 4 or Fe 2 O 3 into bimetallic catalysts has emerged as a promising strategy, offering both economic and material accessibility advantages. [10][11][12][13][14][15][16][17][18][19][20][21][22] In this context, the investigation of Pd-Fe bimetallic magnetic nanocatalysts for eco-friendly chemical processes is particularly intriguing. These catalysts have been utilized in reactions that traditionally depend on specialized and sometimes hazardous ligands and reducing agents, with variants including Fe-Pd/C, Fe-Pd@SiO 2 , and Fe-Pd/ NHC.…”

“…8,9 Leveraging these benefits, the integration of magnetic supports such as Fe 3 O 4 or Fe 2 O 3 into bimetallic catalysts has emerged as a promising strategy, offering both economic and material accessibility advantages. 10–22…”

Dehydration of primary amides to nitriles in water. Late-stage functionalization and 1-pot multistep chemoenzymatic processes under micellar catalysis conditions

“…1 Moreover, the rod-like geometry, around eight times smaller than a methyl group, 2 can be used not only to probe sterically congested pockets, but can also act as a useful bioisostere for oxo-, hydroxyl-, and halogen moieties. 3 Many methodologies have been developed recently to directly add this valuable functional group to existing structures, including substitution, 4 coupling, 5 and addition reactions. 6 From the standpoint of environmentally responsible protocols, we have recently described a procedure that significantly raises the bar on such chemistry, involving introduction of the CN residue onto aryl and heteroaryl halides in water and at the ppm level of Pd catalysis.…”