Efficient synthesis of 5‐substituted tetrazoles catalysed by palladium–S‐methylisothiourea complex supported on boehmite nanoparticles

Abstract

An efficient and general method is reported for the synthesis of 5-substituted 1Htetrazole derivatives in the presence of S-methylisothiourea complex of palladium immobilized on boehmite nanoparticles (Pd-SMTU@boehmite) as an efficient and recyclable nanocatalyst. Boehmite nanoparticles were not sensitive to air or moisture and were prepared without inert atmosphere in water at room temperature. Then a novel type of phosphine-free palladium complex was immobilized on these nanoparticles. This catalyst was characterized using Fourier transform infrared, thermogravimetric, Brunauer-Emmett-Teller, transmission and scanning electron microscopic, energy-dispersive X-ray spectroscopic, X-ray diffraction and inductively coupled plasma optical emission spectroscopic techniques. The catalyst was reused several times without palladium leaching or change in its structure.

A new Pd‐Schiff‐base complex on boehmite nanoparticles: Its application in Suzuki reaction and synthesis of tetrazoles

“…The XRD patterns of Pd‐isatin‐boehmite are shown in Figure . Which the boehmite phase has been identified by the several peak of 2θ at 14.42, 28.41, 38.52, 46.45, 49.54, 51.93, 56.45, 60.72, 65.10, 65.56, 68.12, and 72.42 from the XRD patterns, which is good agreement with standard boehmite XRD spectrum . It could be seen that the boehmite phase has not been destroyed during the modifications.…”

“…Also, tetrazoles and their derivatives have been reported as analgesic, antiviral, anti‐inflammatory, anti‐proliferative, antibacterial, potential anti HIV drug candidate, antifungal, herbicidal and anticancer agents . Likewise, the C‐C band formation has been employed in the synthesis of advanced materials and natural products, pharmaceuticals, agrochemicals and biologically active compounds as well as in engineering materials has attracted enormous interest . The Suzuki cross coupling reaction is one of the most general and powerful tools for the formation C‐C bands …”

Nanomaterial catalyzed green synthesis of tetrazoles and its derivatives: a review on recent advancements

“…Magnetic nanomaterials have number of remarkable features like easy preparation, reusability, high catalytic efficiency, and handy separation from reaction mixtures through an external magnet which makes them ideal and efficient nano-catalyst. [37][38][39] For example, Zarghania and Akhlaghinia have explored magnetitechitin (Fe 3 O 4 @chitin) as an eco-friendly magnetic nanocatalyst for the synthesis of 5-substituted-1H-tetrazoles under solvent-free conditions (Table 2, entry 1). 41 The magnetite-chitin was prepared via a hydrothermal synthesis and characterized with XRD, TEM, SEM, FT-IR, TGA and VSM analytical techniques.…”

Recent Advances in the Synthesis of 5-Substituted 1H-Tetrazoles: A Complete Survey (2013–2018)

“…The [3+2] cycloaddition of benzonitriles with sodium azide in the presence of the S-methylisothiourea complex of palladium immobilized on boehmite nanoparticles (Pd-SMTU@boehmite) in PEG-400 at 120 °C to give 5-aryl-1Htetrazoles in excellent yields (up to 95%) was reported by Ghorbani-Choghamarani and Moradi (Scheme 28). 73 The catalyst could be reused for up to ten cycles without significant loss in its activity and it displayed TOF value of 12.66 h -1 .…”