## 3 Potential Applications in Biological Studies
### Heterocyclic Compounds
The synthetic potential of the prepared compounds was evaluated in reductive or hydrolytic conditions, involving selective carbonate ring-cleavage using diverse nucleophiles (Figure 6) [14]. A new series of \(N\)-phenyl-4,5-dibromopyrrolamides and \(N\)-phenylindolamides was synthetized and a selected set of compounds was evaluated against the enzyme DNA gyrase from _Escherichia coli_ and _Staphylococcus aureus_[128]. [PERSON] and co-workers used ethylene carbonate to prepare \(N\)-aryloxazolidin-2-ones according to Scheme 55. Initially, 3-(4-nitrophenyl)oxazolidin-2-one **62a** was obtained with 81% yield by reacting 4-nitroaniline **63c** with ethylene carbonate **1c** at 100 \({}^{\circ}\)C in the presence of DBU. Subsequent reduction of the nitro group of **62a** provided the corresponding arylamine, which was further coupled with 4,5-dibromo-pyrrole-2-carboxylic acid or indole-2-carboxylic acid to give the target arylcarboxamides **115** and **116**, respectively. However, these compounds showed weaker activities against both _E. coli_ and _S. aureus_ DNA gyrase compared to the reference molecule 2-[[4-(4,5-dibromo-1H-pyrrole-2-carboxamido)phenyl]amino]-2-oxoacetic acid. In 2016, [PERSON] and co-workers [129] described a rhodium(III)-catalyzed, heteroatom-directed C-H allylation process with allylic phosphonates and allylic carbonates. Specifically, the mild and site-selective C-H allylation of 2-arylbenzo[\(d\)]thiazole **117** with vinyl carbonate **1e** provided the allylic alcohol **118** (90% yield) with an \(E/Z\) ratio of 7.5:1 (Scheme 56). This protocol was suitable for a wide range of substrates and may be applicable for accessing new bioactive heterocyclic compounds. A one-pot synthesis method for new \(N\)-3-substituted 2-thiohydantoin **119** was reported starting from GC (Scheme 57) [130]. In this study, a tandem Staudinger reaction was devised to convert primary azides into isothiocyanates, which were further reacted with \(\alpha\)-amino esters. Namely, glycerol carbonate azide **1n** led to isothioxane **1o**, which  
Figure 6: Products obtained from benzimidazole-derived carbonate **107**. was reacted without isolation with \(\alpha\)-amino ester **120** to provide the \(N\)-3-glycerylated compound **119** with 68% overall yield. In 2017, [PERSON] and co-workers [131] described the construction of nine-membered heterocycles via a [5+4] cycloaddition reaction between \(N\)-tosyl azadienes **31** and substituted vinylethylene carbonates **6** under Pd catalysis, involving highly diastereoselective functionalization (Scheme 58). The benzofuran-fused heterocycles **30** were isolated with 85-92% yields after 15 h of reaction. This strategy was applied with high efficiency to various carbonates and azadienes bearing _para-_, _meta-_, or _ortho-_ substituents at the aryl ring with both electron-withdrawing and electron-donating characters. When the unsubstituted vinyl carbonate **1e** was reacted with various \(N\)-tosyl azadienes **31**, the kinetically preferred five-membered ring structure was formed through [3+2] cyclization, and the spirocyclic products **121** were isolated in good yields and with high diastereoselectivity. The same group [132] reported the synthesis of [5,5]- and [6,5]-spiro-heterocycles **123** and **124** through the reaction of aurrones **122** with vinylethylene carbonates **6** under Lewis-acid-assisted Pd catalysis (Scheme 59). Using a simple approach and using commercially available catalysts, the scope of the [3+2] cycloaddition was extended to several enones **122** and carbonates **6** bearing electron-donating or electron-withdrawing substituents at either _para-_ or _ortho-_positions on the aryl group, as well as to naphthyl- and furyl derivatives. Under the optimized conditions, substituted [5,5] products **123** were obtained in high yields, except when alkyl vinylethylene carbonates **6** were used. Additionally, the protocol was applied in [4+2] cycloadditions, targeting the formation of [6,5] spirocyclic structures **124**.