Recent advances in the synthesis of fluorinated heterocycles and a review of recent FDA-approved fluorinated drugs

Abstract

Since the inception of artificial drugs and agrochemicals in human society, the presence of a heterocyclic framework in the drug dominates and this could be due to the inspiration of many heterocyclic compounds from nature with significant and diverse biological activity, which are useful for alleviating different diseases. Furthermore, in recent decades, fluorinated compounds have emerged as a prominent and rapidly growing class, securing a vital role in the research and development of new drugs. This could be attributed to the significant inherent properties of the fluorine atom, which, in many cases, solve the problems related to the metabolic stability of drugs, enhance their lipophilicity, and change the pK_a value in favor of drugs. Now, the belief in fluorinated compounds has become so strong that the judicious incorporation of fluorine into organic compounds has become one of the important tools for improving the chances of getting better therapeutically effective compounds. The fusion of the above two individually dominating fields—heterocyclic framework and fluorine atom—in the potential drug compounds offers an even greater likelihood of discovering therapeutically useful agents. This is one of the main reasons why a significant number of fluorinated heterocyclic drugs are being approved by the FDA each year. Although fluorinated compounds have many benefits, the introduction of fluorine substituents remains challenging; particularly, the introduction of fluorine atoms into heterocyclic frameworks can increase the complexity of synthesis. Over the last few decades, several methods have been developed to introduce fluorine into organic compounds; however, fluorination of heterocyclic compounds remains an elusive task, although it is gradually being addressed. In this review, we present the most recent developments in the fluorination of heterocyclic compounds and discuss the chemistry of fluorinated heterocyclic compounds approved in the last and current years.