**Acknowledgements**

*Current Topics in Chirality - From Chemistry to Biology*

as the intermediates for the generation of enantiomerically pure natural and nonnatural *α*-amino acids by means of the dynamic kinetic resolution. Therefore, keeping the consequence of these molecules in mind, König's group in 2013 developed a simple and eco-friendly method for the synthesis of 1,3,5-trisubstituted hydantoin derivatives (**93**/**94**) in excellent yields by means of DMU/TA melt-mediated green approach (**Figure 7**) [52]. Interestingly, during their experimentation, they noted down good diastereoselectivity in which *anti*-isomers were isolated in major amount whileas *syn*-diastereomers were obtained as minor products, confirmed by nuclear overhauser effect (NOE) and X-ray analysis means. On another front, quite recently, Kotha's team has reported mono-hydantoins as well as thiohydantoins by means of three component reaction under low melting mixture of DMU/TA with electron neutral, electron donating, and electron withdrawing groups possessing aniline derivatives (**Figure 7**) [53]. Finally, the tetrahydropyrimidinones (**80**) and quinazoline derivatives (**88**) have been reported, by the groups of Baskaran and Zhang, respectively by employing the same low melting mixture of DMU/TA under similar

*A variety of heterocycles assembled by employing the DMU/TA melt.*

reaction conditions as can be inspected from the **Figure 7** [54, 55].

In summary, a novel method involving DMU/TA as a low melting mixture has comprehensively been revealed in this chapter, depicting its pivotal role in the heart of modern synthetic organic chemistry particularly for the generation of a variety

**16**

**Figure 7.**

**4. Conclusions and outlook**

Dr. Rashid Ali is grateful to DST-SERB New Delhi for financial support (Project File no. ECR/2017/000821). In addition, he also thanks Jamia Millia Islamia, New Delhi, India, for providing the necessary research facilities.
