Pd on the Composite of Perlite and Allylamine-N-isopropylacrylamide Copolymer: A Thermo-Responsive Catalyst for Hydrogenation of Nitroarenes under Mild Reaction Condition

Abstract

A novel thermo-responsive catalyst for the hydrogenation of nitroarenes under mild reaction condition was devised. To prepare the catalyst, a thermo-responsive polymer was first synthesized through the co-polymerization of N-isopropylacrylamide and allylamine and then covalently grafted on the Cl-functionalized perlite. The resulting composite was subsequently utilized as a support for the stabilization of Pd nanoparticles. Investigation of the catalytic activity of the catalyst approved its high catalytic activity at a temperature above the lower critical solution temperature. More precisely, 0.03 g of the catalyst can promote the reaction of 1 mmol of nitro-compounds in H2O/EtOH (1:1) at 45 °C to furnish the corresponding products in 70–100% yields. This issue was assigned to the collapse of the polymeric component and formation of a hydrophobic environment that was beneficial for the mass-transfer of the hydrophobic nitroarenes. Notably, the catalytic activity of the catalyst was higher than that of palladated perlite and thermos-responsive polymer due to the synergistic effects between the perlite and polymeric moiety. Furthermore, the study of the substrate scope confirmed that a wide range of substrates with different steric and electronic properties could tolerate hydrogenation reaction. Moreover, the catalyst was highly selective toward hydrogenation of the nitro group and could be recycled up to seven runs with insignificant Pd leaching and loss of catalytic activity. The hot filtration test also confirmed the heterogeneous nature of the catalysis.

Dual pH- and Thermo-Sensitive Poly(N-isopropylacrylamide-co-allylamine) Nanogels for Curcumin Delivery: Swelling–Deswelling Behavior and Phase Transition Mechanism

“…Figure 1a shows a 1 H NMR spectrum in which the proton resonance peak is at δ1.21 ppm and the resonance peak at δ3.79 ppm, indicating the methyl and amide groups of NIPAm monomer [14]. In addition, the resonance peak arose in the δ1.89-δ2.28 ppm region, confirming the existence of primary amine signals from the Am comonomer [15]. The 1 H NMR spectra revealed the presence of NIPAm and Am in the p(NIPAm-co-Am) NG copolymer NG segments.…”

Pd on cyclotriphosphazen-hexa imine decorated boehmite as an efficient catalyst for hydrogenation of nitro arenes under mild reaction condition

“… Entry Catalyst Temp. (°C) Solvent Time (min) H2 Pressure Yield (%) Reference 1 Pd/B-CP-HIm (0.03 g) 50 H 2 O: EtOH (1:1) 120 1 atm 100 This work 2 Pd/PPh3@FDU‐12 (8.33 × 10 –4 mmol Pd) 40 EtOH 60 10 bar 99 30 3 APSNP a (1 mol%) r.t EtOH 120 40 atm 100 31 4 Pd@Per-P b (0.03 g) 45 H 2 O: EtOH (1:1) 90 1 atm 98 32 5 Pd@CS-CD-MGQDs c (0.5 mol%) 50 H 2 O 60 1 atm 97 33 6 PdNP(0.5%)/Al 2 O 3 (0.3 g) r.t THF 180 1 atm 100 34 7 …”

Highly selective reduction of nitro compounds catalyzed by MOF‐derived glucose stabilized Fe3O4 under mild conditions

“…In line with the ongoing research and growing interest in the synthesis and application of heterogeneous catalysts as well as the pursuit of environmentally friendly approaches to enhance chemical reactions, [36][37][38][39][40][41][42][43][44] this study presents a novel method for synthesizing catalysts based on MOFs. The catalyst are prepared by conjucating cyanuric chloride (TCT) and imidazole (IMI) with aspartic acid, which is then decorated with Fe 3 O 4 .…”