An effective one‐pot method for the conversion of carbon dioxide, ethylene oxide, and amines to 3‐aryl‐2‐oxazolidinones has been developed. This one‐pot method consists of two parallel reactions and a subsequent cascade reaction between the two products of the corresponding parallel reactions. Notably, the binary ionic liquids of 1‐butyl‐3‐methyl‐imidazolium bromide and 1‐butyl‐3‐methyl‐imidazolium acetate demonstrate a synergistic catalytic effect on this new strategy. 1‐Butyl‐3‐methyl‐imidazolium bromide is essential in two parallel reactions owing to the good nucleophilicity and leaving ability of bromide, and 1‐butyl‐3‐methyl‐imidazolium acetate plays a dominant role in the subsequent cascade reaction owing to the strong basicity of acetate. In addition, the binary ionic liquids can be used thrice without significant loss of catalytic activity.

We have investigated the reactions of cyclic carbonates/trithiocarbonate and aromatic amines in the presence of a basic ionic liquid, 1butyl-3-methylimidazolium acetate (BmimOAc), which produced various cyclic carbamates/dithiocarbonimidates in fairly good to excellent yields. The use of BmimOAc as catalyst here not only offers an effective approach to the synthesis of the target compounds, but also avoids the use of conventional toxic materials. By means of the reactions of cyclic carbonates and aromatic amines, 3-aryloxazolidin-2-ones, 3,3'-aryldioxazolidin-2-ones and 3-arylA C H T U N G T R E N N U N G [1,3]oxazinan-2-ones could be synthesized. NMR spectroscopy and DFT calculations revealed that both the cation and the anion of BmimOAc activate cooperatively the substrates in these reactions by means of inducing hydrogen bonding. In addition, condensation reactions of ethylene trithiocarbonate and aromatic amines also proceeded very well in the presence of the BmimOAc catalyst, which opened a hitherto unreported route to [1,3]dithiolan-2-ylidene-arylamine derivatives in a straightforward way.

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Liquids. -All yields determined by GC-analysis. -(WANG, B.; ELAGEED, E. H. M.; ZHANG, D.; YANG, S.; WU, S.; ZHANG, G.; GAO*, G.; ChemCatChem 6 (2014) 1, 278-283, http://dx.

BmimOAc. -The reaction of cyclic carbonates with a variety of aromatic and heteroaromatic amines is advantageously achieved in [bmim]OAc as catalytic solvent to yield cyclic carbamates. The analogous cyclic trithiocarbamate (IX) yields 1,3-dithiolan--2-ylidene-arylamines under similar conditions. -(WANG, B.; YANG, S.; MIN, L.; GU, Y.; ZHANG, Y.; WU, X.; ZHANG, L.; ELAGEED, E. H. M.; WU, S.; GAO*, G.; Adv. Synth. Catal. 356 (2014) 14-15, 3125-3134, http://dx.