Fatemeh Mohammadsaleh*^a, Maryam Dehdashti Jahromi^b, Abdol Reza Hajipour^cd, Seyed Mostafa Hosseini^c and Khodabakhsh Niknam*^a
aDepartment of Chemistry, Faculty of Nano and Bio Science and Technology, Persian Gulf University, Bushehr, Iran. E-mail: f.mohammadsaleh@gmail.com; niknam@pgu.ac.ir
^bFaculty of Engineering, Jahrom University, Jahrom, Iran
^cPharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, Islamic Republic of Iran
^dDepartment of Pharmacology, University of Wisconsin, Medical School, 1300 University Avenue, Madison, 53706-1532 WI, USA

Received 29th April 2021 , Accepted 4th June 2021

First published on 11th June 2021

Abstract

1,2,3-Triazole is an interesting N-heterocyclic framework which can act as both a hydrogen bond donor and metal chelator. In the present study, C–H hydrogen bonding of the 1,2,3-triazole ring was surveyed theoretically and the results showed a good agreement with the experimental observations. The click-modified magnetic nanocatalyst Pd@click-Fe₃O₄/chitosan was successfully prepared, in which the triazole moiety plays a dual role as both a strong linker and an excellent ligand and immobilizes the palladium species in the catalyst matrix. This nanostructure was well characterized and found to be an efficient catalyst for the CO gas-free formylation of aryl halides using formic acid (HCOOH) as the most convenient, inexpensive and environmentally friendly CO source. Here, the aryl halides are selectively converted to the corresponding aromatic aldehydes under mild reaction conditions and low Pd loading. The activity of this catalyst was also excellent in the Suzuki cross-coupling reaction of various aryl halides with phenylboronic acids in EtOH/H₂O (1:1) at room temperature. In addition, this catalyst was stable in the reaction media and could be magnetically separated and recovered several times.