Chiral (Stereoselective) Drugs, Asymmetric Synthesis, and Racemic Resolution Methods

Chirality is of great importance in drug development since both biological targets in the organism and the majority of pharmacologically active compounds created today are chiral. The synthesis and resolution of chiral compounds are critical steps while developing chiral drugs, as the chirality of a molecule can significantly affect its efficacy, safety (side effects and toxicity), and metabolism. While one enantiomer has therapeutic properties, the other enantiomer might be harmful, toxic, or ineffective. In recent years, the trends towards developing single enantiomer drugs have increased in the pharmaceutical industry. Various synthetic strategies and racemic resolution techniques are employed to obtain optically pure chiral drugs. Regulatory authorities also give more priority to assessing the biological efficacy of each chiral drug's enantiomer. This review summarizes the asymmetric synthesis and racemic resolution methods for producing pure enantiomeric pharmaceutical active ingredients and their synthetic intermediates, with examples from the pharmaceutical industry. By examining current approaches and challenges in the field, we aim to provide a comprehensive understanding of the processes that ensure the production of safe and effective chiral-specific drugs.