Different Route of Synthesis of Schiff Base‐Metal Complexes

Schiff bases (SBs) can be synthesized by various chemical routes using different substrates or reactants. The first and general route is the condensation of primary amine and aldehyde/ketone under refluxing conditions. However, several other possible synthetic routes are observed by the use of reactants like cyanides, nitriles, phenols, metal amides, phenolic ethers, metal amines, oximes, nitroso compounds, ketals, olefins, and amino acids. Microwave irradiation method for the synthesis of SB is a greener chemical method which is considered as simple, convenient, sensitive, and solvent-less method. The SB formation reaction that involves the use of water encourages the researcher as water is easily available and reactions are eco-friendly. The ultrasonic method utilizes environmentally benign sonochemical waves for ultrasonic irradiation. This method speeds up the reaction and decreases the completion time. Green method utilizes green catalysts like natural acid and green waste peel powder for the synthesis of SBs from several aldehydes and substituted amines.