Quantum-Chemical Study on Reactions of Isocyanates with Linear Methanol Associates: III.* Reaction of Methyl Isocyanate with Linear Methanol Associates

Addition of linear methanol associates at the C=N and C=O bonds of methyl isocyanate was studied in terms of the B3LYP/6-311++G(df,p) hybrid quantum-chemical method. The addition at the C=N bond is more favorable than the reaction at the carbonyl group. All reactions involve late asymmetric cyclic transition states. The activity of the reacting system increases in parallel with the degree of methanol association. Isomerization of methyl hydrogen methylcarbonimidate into carbamate is catalyzed by methanol associates. Thermal decomposition of carbamates with formation of isocyanates can occur in autocatalytic mode.