A novel nanomagnetic palladium (II) complex of bisimidazolium-based Nheterocyclic carbene; An efficient heterogeneous catalyst for A3 coupling reactions

• Published in: Journal of molecular structure 2023-10, Vol.1290, Article 135911
• Main Authors: Althomali, Raed H., Abbood, Mohammed Khalid, Altalbawy, Farag M.A., Saleh, Ebraheem Abdu Musad, Abdullaev, Sherzod Shukhratovich, Ibrahim, Ahmed jaber, Ansari, Shakeel Ahmed, Romero-Parra, Rosario Mireya
• Format: Article
• Language: English
• Subjects: [Fe3O4@bisimidazolium-Pd]2Cl; A3 coupling; Bisamide ligand; NHC-palladium complex; Propargylamines
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2023.135911

•Pd (II) complex of bisimidazolium-based NHeterocyclic carbene heterostructure catalyst was successfully fabricated via a facile method.•It has excellent catalytic capacity for A3 coupling reaction.•The catalyst was used in the synthesis of a library propargylamine derivatives.•The catalyst can be reused seven times without remarkable loss of catalytic activity. Herein, a novel nanomagnetic NHC-Palladium complex was successfully prepared applying post-synthetic modification (PSM) condensation between Fe3O4-support imidazole and a synthetic bisamide moiety, carrying the alkyl halide functionalities at the end of its chain, followed by chelation of Pd ions to generate the corresponding complex. The [Fe3O4@bisimidazolium-Pd]2Cl− complex gave the best catalytic performance in synthesizing propargylamines through A3 coupling of various substituted aromatic and cycloaliphatic aldehydes and secondary amines with aromatic and liner alkynes in PEG-400. Primary amines are inefficient to produce unknown byproducts; whereas, secondary amines react quickly. Significantly, alkynes having a high electron density reduce the conversion rate. Moreover, aromatic and aliphatic aldehydes are active, but the electron-drawing substituent on benzaldehyde decreases the rate of conversion. Furthermore, the [Fe3O4@bisimidazolium-Pd]2Cl− catalyst can be reused seven times without metal leaching or losing its ability, which shows how stable it is when used in a reaction. [Display omitted]