Simple and efficient synthesis of 5‐substituted 1‐H‐tetrazoles using metal‐modified clay catalysts

Abstract

The synthesis of 5-substituted 1-Htetrazoles based on reaction of a series of aromatic

Tetrazoles: calcium oxalate crystal growth modifiers

“…The methods of synthesising tetrazoles has been extensively researched [12][13][14][15][16][17][18][19] due to the multitude of applications of tetrazole-containing compounds, including the use of tetrazoles in materials science and medicinal chemistry. 20,21 Tetrazoles have been increasingly used in medicine due to their bioisostere nature with carboxylic acids.…”

β‐Cyclodextrin: A Green and Efficient Supramolecular Catalyst for Organic Transformations

“…Sharpless and co‐workers reported a “click” chemistry approach for synthesis of tetrazoles by [2+3] cycloaddition of nitriles and NaN 3 using stoichiometric amounts or 50 mol % of Zn(II) salts,, but still requires tedious time consuming steps such as removal of zinc salts from acidic products. Several new pathways have been developed such as use of metal complexes as a catalyst, use of TMSN 3 −TBAF, micellar media and ionic liquids, Zn/Al‐hydrocalcite, Sb 2 O 3 , Mesoporous ZnS nanospheres, silica sulfuric acid, metal modified clay catalyst, ZnO in microwave, ZnCl 2 under solvent free condition, ZnBr 2 in microwave, use of clay‐Montmorillonite K‐10, Kaoline,, use of various azide salts, microwave irradiation,, Et 3 N.HCl in nitrobenzene under microwave irradiation., CdCl 2, FeCl 3 −SiO 2 as acidic heterogeneous catalyst, iodine or silica supported sodium hydrogen sulfate (NaHSO 4 ⋅ SiO 2 ), CoY zeolite, using copper acetate, InCl 3 , copper catalyzed microwave irradiation, sulfamic acid, etc. However, some methods still require long reaction times to achieve reasonable yields and tedious work‐up and purification of products.…”

Homoselective synthesis of 5‐substituted 1H‐tetrazoles and one‐pot synthesis of 2,4,5‐trisubstuted imidazole compounds using BNPs@SiO2‐TPPTSA as a stable and new reusable nanocatalyst

“…[ 14 ] 1,3‐Dipolar cycloaddition is an effective route for the preparation of tetrazoles. [ 15 ] Up to now, varied catalysts like Lewis acids, AgNO 3 , [ 16 ] Fe(OAc) 2 , [ 17 ] In(OTf) 3 , [ 18 ] BF 3 ‐OEt 2 , [ 19 ] Yb(OTf) 3 , [ 20 ] Cu 2 O, [ 21 ] modified montmorillonite clays, [ 22 ] MNPs@NHC(O)CH2CH2PPh2, [ 23 ] and natrolite zeolite [ 24 ] have also been documented to the preparation of 5‐substituted 1 H ‐tetrazoles. [ 25 ] So far, many protocols for the construction of tetrazole derivatives have been reported, but the development of useful techniques is still needed because of some drawbacks of previous methods like the use of poisonous metals, usage of organic solvents in particular (DMF), strong Lewis acids, rigid reaction conditions, high‐cost reagents, low yields, and use of hydrazoic acid, which is poisonous and dangerous.…”