Fe₃O₄@SiO₂–ZrCl₂‐MNPs: A novel magnetic catalyst for the clean and efficient cascade synthesis of 1‐(benzothiazolylamino)methyl‐2‐naphthol derivatives in the absence of solvent

Abstract

A green, simple and eco-friendly three-component condensation for the synthesis of 1-(benzothiazolylamino)methyl-2-naphthols using new magnetic nanoparticles formulated as Fe 3 O 4 @SiO 2 -ZrCl 2 -MNPs is described. Considering the economic and environmental aspects, the method provides some advantages such as clean procedure, solvent-free conditions, simple operation and work-up, relatively short reaction times and high yields of the products. Moreover the introduced catalyst can be readily recovered up to 4 consecutive runs with consistent activity using an external magnet.

4‐(4‐Propylpiperazine‐1‐yl)butane‐1‐sulfonic acid‐modified silica‐coated magnetic nanoparticles: A novel and recyclable catalyst for the synthesis of 5‐arylidinebarbituric acids and pyrano[2,3‐d]pyrimidinedione derivatives in aqueous media

“…In recent years, the introduction of new catalysts for the promotion of organic reactions has become an important part of our ongoing research programme . Herein and in continuation of these studies, we report the use of our novel magnetic Fe 3 O 4 ‐based nanoreagent formulated as Fe 3 O 4 @SiO 2 ‐Propyl‐Pip‐SO 3 H.HSO 4 as a catalyst in the preparation of 5‐arylidinebarbituric acids and pyrano[2,3‐ d ]pyrimidinedione derivatives.…”

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

“…This strategy involves heating an aqueous mixture of 2-naphthol 406, aldehydes 4 and 2-aminobenzothiazole 3b together with 20 mol% of SDS at 100 °C for 1–3 h, resulting in the construction of C–C and C–N bonds. 235 Since then, a number of reactions have been carried out for the synthesis of 1-(benzothiazolylamino)methyl-2-naphthol derivatives 407 based on the same platform with the help of catalysts/promoters such as NaHSO 4 ·H 2 O, 236 heteropolyacid (HPA) as a heterogenous catalyst, 237 rice husk ash (RHA)-supported 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate (RHA-[pmim]HSO 4 ) as an acidic ionic liquid, 238 KOH-loaded MgO/hydrotalcite as a basic catalyst, 239 oxalic acid as an organocatalyst, 240 MPIL B, 241 NH 3 (CH 2 ) 5 NH 3 BiCl 5 , 242 Fe 3 O 4 @SiO 2 -Propyl-Pip-SO 3 H·HSO4, 243 γ-aminobutyric acid and isinglass a collagen peptide, 244 Fe 3 O 4 @SiO 2 @(CH 2 ) 3 -urea-SO 3 H/HCl, 245 Fe 3 O 4 @SiO 2 –ZrCl 2 -MNPs, 246 and (rMGO)-Au NPs 247 ( Scheme 135 ). The reaction mechanism for the formation of Betti's base proceeds though an o -QM intermediate 407a, which is generated from the condensation of 2-naphthol with aldehyde in the presence of a suitable catalyst.…”

One‐pot Suzuki Coupling‐Knoevenagel Condensation Tandem Reaction Catalyzed by a Recyclable Magnetic Bifunctional Catalyst

“…[50] In addition, magnetically recoverable nanoparticles supported catalysts showed better catalytic activity than many traditional catalysts in organic synthesis. [52][53][54][55][56][57][58] It's a promising way to catalyze one-pot tandem reaction with magnetic nanoparticles supported bifunctional catalysts. Recently, we designed and synthesized a magnetic nanoparticles supported amine-palladium bifunctionalized catalyst NHÀ Pd(0)@MNP (Figure 1.…”