| Abstract: | Title reactions were investigated with ab initio calculations. Methyl isocyanate and ethylene oxide were adopted as model reactants. The products, 2‐oxazolidones and isocyanurates, cannot be yielded without a base catalyst. The 2‐oxazolidone may be produced by a dual SN2 reaction, where the catalyst base (e.g., Cl−) is a nucleophile and a leaving group on the ethylene–oxide carbon. Isocyanurate is generated by the stepwise association of three isocyanate molecules, where one of the molecules is initially linked with a base. The six‐membered ring isocyanurate is isomerized stepwise into the components isocyanate and 2‐oxazolidone. A tetrahedral type of complex between the isocyanurate and a base‐catalyzed ethylene oxide is the key intermediate for the isomerization. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 316–326, 2001 |
