Preparing Pd catalysts based on urea ligand via electrospinning for Suzuki–Miyaura cross‐coupling reactions

Abstract

Pd‐catalyzed Suzuki–Miyaura cross‐coupling (SMC) reactions are important in chemistry. In this work, using electrospinning technology, we prepared a novel type of composite catalyst with ligand structures such as urea‐Pd/PAN (polyacrylonitrile) and used them to catalyze SMC reactions in nontoxic systems and “green” conditions (air atmosphere, low temperature, and short reaction time). This method of preparing hybrid materials is simple and easy to operate. The higher catalytic activity of the catalysts is attributed to active centers with rich electrons transferred from ligands with unique structures, which can decrease the activation energy of the rate‐determining step (oxidative addition). In addition, urea‐Pd/PAN composite catalysts exhibit higher catalytic performance than those reduced by H2 because of the smaller size of active species and the more‐efficient oxidative addition to Pd0–ligand complexes compared to Pd0.

N,N′-Dimethylurea as an efficient ligand for the synthesis of pharma-relevant motifs through Chan–Lam cross-coupling strategy

“…57 Urea-based ligands are particularly useful in anion recognition by hydrogen bonding [58][59][60][61][62][63] and in asymmetric catalysis. 64 Ureas are useful as ligands to Pd for achieving more efficient Suzuki-Miyaura cross-couplings 65 and "phosphine ligand-free" Heck couplings. 66,67 In addition to that, ureas and thioureas were also used to achieve the hydrogenation of ketones and epoxides, 68 enantio-selective reduction of acetophenone, 69 as alternative green ligands to reprotoxic NMP, 70,71 and heteroannulation reactions.…”

New Benzimidazole‐Based Fe (III) and Cr (III) Complexes: Characterization, Bioactivity Screening, and Theoretical Implementations Using DFT and Molecular Docking Analysis

“…[17] Because of the frequent occurrence of mixed chelation in biological fluids, mixed ligand complexes play a significant role in biological and catalytic chemistry. [18][19][20] Mixed ligand complexes synthesis and characterization are becoming more and more important. This inspires the creation of mixed ligand complexes with a range of characteristics.…”

Palladium nanoparticles encapsulated in polyimide nanofibers: An efficient and recyclable catalyst for coupling reaction

“…Till now, various synthetic-and biopolymers (e.g., poly[vinyl alcohol], polyacrylonitrile, and cellulose) have been successfully electrospun into nanofibers. [12][13][14] Among various polymers, polyimides (PI) are well known for their superior thermal property and chemical resistance as well as mechanical properties. [15,16] PI nanofibers based on pyromellitic dianhydride (PMDA) and 4,4 0 -oxidianiline (ODA) have been prepared by electrospinning the precursor of polyimide, a poly(amic acid) (PAA) solution, with subsequent thermal imidization.…”