## 2 Applications in Chemistry
### Other Reactions  
Due to their favorable nutritional properties, 1,3-diglycerides, i.e., 1,3-\(sn\)-diacylglycerols **3a**, are popular in the food industry. Interestingly, these diglycerides may be synthetized by an efficient and benign two-step, one-pot process, without any solvent (Scheme 34) [98]. A practical method used fatty acid anhydrides **60** and GC **1a** under DABCO catalysis to produce the industrially relevant diglycerides **3a** with good yields and high purity. Long-chain anhydrides **60** of lauric, myrsitic, palmitic, and stearic acids **61** led in all cases to the esterified carbonates, which were isolated in similar yields after 7 h reaction. Two plausible mechanisms were suggested for their transformation into **3a**. First, the liberated fatty acid **61** reacts with DABCO to form an ammonium salt. The carboxylate anion can subsequently attack either the alkylene carbon (route 1) or the carbonyl group of the esterified carbonates (route 2), providing the desired **3a**. The formation of the product was monitored by observing the liberation of CO\({}_{2}\) and the disappearance of the carbonate IR band of the esterified carbonates. Poly(ionic liquid)s (PILs) represent an emerging interdisciplinary topic due to their potential applications in chemistry, physics, materials science, and electrochemistry [99; 100]. In this sense, the application of nonporous PIL beads with swelling properties as catalysts for the reaction of ethylene carbonate with aniline was proposed by [PERSON] and co-workers (Scheme 35) [101]. After preparation of cross-linked poly(ionic liquid)s by direct radical copolymerization of \(N\)-vinyl imidazolium ionic liquids with sodium acrylate, the authors used them in the conversion of various carbonates. Due to its swelling ability, P[VBIM][AA] presents catalytic activities similar to the homogeneous ionic liquid monomers. However, cyclic carbonates with a low dielectric constant, such as propylene- and 1,2-butylene carbonate, showed different swelling abilities, thus decreasing the catalytic activity and providing the corresponding oxazolidones **62** in lower yields (50% and 2%) than with ethylene carbonate **1** (99%). With a view to avoiding purification steps, [PERSON] and co-workers [102] reported the one-pot synthesis of glycols **12** via in situ formation of glycerol carbonate **1a** in the absence of any solvent. By reacting different phenols **7** with glycerol **3** (3 equivalent) and diethyl carbonate **16b** (1.4 equivalent) under K\({}_{2}\)CO\({}_{3}\) catalysis, glycols **12** were obtained with 72-82% yields (NMR evaluation) under conventional conditions (Scheme 36). 1-Naphth was also successfully converted into the corresponding diol with 74% yield after 18 h.  
The proposed method allowed seven aryloxypropanediols to be obtained, three of which were pharmaceutically important products, namely guaiphenesin,  
Figure 34: Synthesis of diglycerides **3a** from fatty acid anhydrides **60** and GC **1a** under DABCO catalysis. and chlorophenesin (Figure 5). To check the recyclability of excess glycerol and of the catalyst after the first run, prephenesin was extracted with toluene, then 1 equivalent of _o_-cresol, 1.4 equivalent of glycerol, and 1.4 equivalent of diethyl carbonate were added to the recovered residue. The resulting mixture was then stirred at 105-110 \({}^{\circ}\)C over 28 h. Although prephenesin could be obtained with good yields (76-80%) after three consecutive runs, the study of the re-use of the glycerol and base was not further developed. A tetrabutylammonium-fluoride-mediated hydroxyalkylation process for phenols **7** with carbonate **1c** was developed to access different aryl \(\beta\)-hydroxy ethyl ethers **64**[103]. In this process, the corresponding products were obtained with 88-98% yields by using TBAF.3H2O (1 mol%) in DMF as the solvent at 170 \({}^{\circ}\)C, under N2 atmosphere over 13 min to 21 h of reaction (Scheme 37). Different substituted phenols were employed and good yields were obtained.