Chemistry and Applications of Functionalized 2,4-Thiazolidinediones

Thiazolidinedione (TZD) is one of the privileged heterocyclic rings and has shown many biological applications in medicinal chemistry and drug discovery. This review covers the synthetic approaches of TZD and its derivatives, different synthetic techniques for affording the desired regioselectivity and stereoselectivity, and the techniques that would enhance reaction conditions such as microwave, one-pot, or ultrasound synthesis. It focuses on synthetic challenges of glitazones and the transformation of other heterocycles to TZD. Moreover, the chemical and biological behavior of TZD through the substitution in the N3 position, modification of the C5 position, annealing in complex heterocyclic systems, and hybridization with other pharmacologically attractive moieties are discussed. All reactions mentioned are provided as possible with different reaction conditions, mechanisms, derivatives scope, yield and clarified by applications of such reactions in the construction of potential medicinal agents. The review also answers questions about rapid racemization of glitazones, their toxicity, considering TZD as pan-assay interference compounds (PAINS) or not, and the influence of saturation of 5-position of TZD in their biological activities. This review is a comprehensive guide to make informed decisions for construction of TZD derivatives with biological potentials.