The present work provides a fast and mild method towards the synthesis of urea derivatives and their application in amino group protection. This new methodology is an inexpensive, simple, and environmentally safe process for the synthesis of urea derivatives. It is well suited for aliphatic amines and aromatic amines. With aliphatic amines, Zn-mediated urea bond formation occurs at ambient temperature, whereas with aromatic amines, it occurs at 60 degrees C. Environmentally friendly reaction conditions, sustainability, enumerating tolerance of a wide variety of functional groups, cost-effectiveness, high atom economy, fast reaction time, and adaptability for large-scale synthesis are all benefits of this technology.

Herein, we report a microwave-assisted synthesis of 2-oxazolines from a carboxylic acid and amino alcohol by using dehydrating reagent carbonyl diimidazole (CDI). The developed methodology was successfully utilized for the synthesis of key intermediate oxazoline 2k (methyl 2-(2-hydroxyphenyl)-4,5-dihydrooxazole-4-carboxylate) of natural products Mycobactin S, Mycobactin T, and Spoxazomicin C. The salient features of this synthetic method are low reaction time, high yield, one-pot synthesis, and no requirement for harsh reaction conditions.

Epilepsy is a chronic neurological disorder in the brain, affecting individuals of all age groups. Nearly 1% of the world population is affected by seizure disorder, of which 80% of the patients are observed in underdeveloped and developing countries. The predominant treatment option for epilepsy includes an antiepileptic drug named brivaracetam. This drug emerged as an unusual success of rational drug discovery in clinical development by exhibiting magnificent affinity toward synaptic vesicle glycoprotein as compared to conventional drug levetiracetam and piracetam. Given its efficiency in limiting the progression of epilepsy, this drug has drawn considerable attention of researchers to devise novel routes of its synthesis. The present review encapsulates the reported literature on synthetic strategies for brivaracetam, which will assist medicinal chemists in the further progress of its synthesis.

Due to global warming, with climate changes and significantly decreasing petrochemical resources, an urgent need has arisen to produce bio-based products in a renewable manner. Chemical-based products also cause a serious impact on health and the environment. Chemical synthesis and extraction of products from plants are non-sustainable. The global demand for natural flavor and fragrance is continuously increasing and has shown a high interest in the aroma industry. Plants and microorganisms are the major sources of flavor and fragrance. Due to production in smaller concentrations, isolation and extraction of such value-added chemicals become expensive. These natural products are terpenoids, aldehydes, methyl ketones, etc., which are used in a wide range of domestic products including cosmetics, soaps, fresheners, candles, and foods. Microbial production is an alternative way of synthesis by modifying natural biosynthetic pathways or inserting a novel pathway into hosts. The present chapter highlights important chemicals for flavor and fragrance and their engineered production.

Vanillin containing 9H-fluoren sulfone scaffolds were prepared by coupling a sulfone amine with carboxylic acid group of amino acids in presence of peptide coupling reagent hexafluorophosphate benzotriazole tetramethyl uronium (HBTU). All eight (6a–6h) synthesized vanillin containing 9H-fluoren sulfone scaffolds were evaluated for their biological activities, namely, antibacterial, antifungal and antimalarial. The antibacterial evaluation revealed that compounds 6b-6g exhibited potency against tested pathogenic bacteria, especially against Staphylococcus aureus. Compounds 6b, 6f and 6h manifested considerable antifungal activities against Candida albicans, Aspergillus niger and A. clavatus. Moreover, the antimalarial result demonstrated excellent antimalarial activities for compounds 6b and 6f against Plasmodium falciparum with IC50 less than the standard quinine. Further, molecular docking study was performed to find molecular level interaction of compounds with malarial drug target enzyme P. falciparum dihydrofolate reductase-thymidylate synthase (pfdher-ts). Interestingly, for all tested sulfone scaffolds the docking energy was found between −8.6 to −10.6 kcal/mol, which was higher than both of the standard drugs' (quinine and chloroquine) docking energy, i.e. −8.4 and −6.9, respectively. The results of this study confirmed the importance of the sulfone class of compounds in the treatment of parasitic infections and microbial infections.

Psoriasis and psoriatic arthritis are immune-mediated chronic inflammatory disorders which predominantly involve skin and joints. Around the world, it has affected nearly 38 million people worldwide. In 2014, Celgene Corporation's (S)-apremilast was introduced to treat patients suffering from the different types of psoriasis. In this review, we discuss the different strategies for the synthesis of (S)-apremilast which will help further develop novel routes for its synthesis.

A formal, stereoselective synthesis of Aspergillide-B is described. A highly diastereoselective Pd(0)-B(OPh)(3) mediated syn-vic-diol formation from epoxy unsaturated ester used for the creation of C3-C4 centres. Iodine catalyzed allylation used for synthesis of trans-2,6-disubstitutedtetrahydro-2H-Pyran. Cross- metathesis, Yamaguchi macrolactonization are the other key features of the synthesis.

The first total syntheses of diarylheptanoid natural products (2R,4S,6R)-2-(4-hydroxyphenethyl)-6-(4-hydroxyphenyl) tetrahydro-2H-pyran-4-ol (4) and (3R,5R)-1,7-bis (4-hydroxyphenyl)heptane-3,5-diol (12) were accomplished using substrate selective hydrogenation, ring cleavage of tetrahydropyran ring, and Keck–Maruoka allylation as the key synthetic steps.

A new method for the stereoselective synthesis of trans 2.6-disubstituted tetrahydro-2H-pyrans has been developed involving iodine catalyzed allylation of tetrahydro-2H-pyranol with excellent trans selectivity. The method was also applied toward the construction of C1–C13 fragment of bistramide-A in 11 steps with 21.4% overall yield.

A stereoselective synthesis of the C1–C11 fragment of zincophorin was achieved by using an intramolecular oxetane ring opening reaction as the key step. The oxetane moiety was synthesized by employing a desymmetrization protocol developed at our group and a non-Evans syn aldol as the key steps toward the synthesis.