Recent Advances in the Synthesis of Highly Substituted Piperidine Analogs with Biological Activities

The development of novel techniques for the efficient construction of heterocyclic compounds is an major issue in the preparation of organic compounds. The piperidine building block acts as a substantial task in the inhibitory activity of compounds and thus is very important in influencing biological properties such as antioxidant, anti-Alzheimer and free radical scavenging activities. Highly substituted piperidine analogs play a remarkable role in the synthesis of pharmaceutical compounds as important structural components in active and natural biological compounds. This review summarized advances in the synthesis of highly substituted piperidine analogs and their antioxidant and anti-Alzheimer properties. Antioxidant activities are inversely proportional to IC50 value. In addition, new green methods for the preparation of piperidine building blocks, such as: non-toxic catalysis, water-initiated processes, solvent-free reactions, etc., are also presented. This review study is designed to assist scientists looking for suitable substrates for the construction of biologically active piperidine analogs.