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CO2 was investigated as carbon source for the synthesis of the polymer precursor toluene‐2,4‐diisocyanate (TDI). A four‐step synthesis was envisaged. The first step, i.e., the Ru‐catalyzed CO2 hydrogenation to [HCOOH·amine] adducts, was carried out under biphasic conditions allowing for straightforward reutilization of the catalyst phase. The investigation of the second step, the esterification of formic acid with methanol to yield methyl formate (MF), is ongoing with a strong focus on the integration with the hydrogenation step. The potential hazards of the third step, the Pd‐catalyzed oxidative carbonylation of toluene‐2,4‐diamine with MF, have been addressed developing a sophisticated protocol for a safe operation with organics/CO/O2 mixtures. For the final step, the carbamate cleavage of toluene‐2,4‐dicarbamate (TDC) towards TDI, monofunctional model substrates and TDC were cleaved in the presence of bifunctional catalysts. The obtained kinetic data allowed to implement the reaction in a continuous stirred‐tank reactor and will serve as starting point for further process optimization.

The chemistry of urethanes plays a key role in important industrial processes. Although catalysts are often used, the study of the reactions without added catalysts provides the basis for a deeper understanding. For the non‐catalytic urethane formation and cleavage reactions, the dominating reaction mechanism has long been debated. To our knowledge, the reaction kinetics have not been predicted quantitatively so far. Therefore, we report a new computational study of urethane formation and cleavage reactions. To analyze various potential reaction mechanisms and to predict the reaction rate constants quantum chemistry and transition state theory were employed. For validation, experimental data from literature and from own experiments were used. Quantitative agreement of experiments and predictions could be demonstrated. The calculations confirm earlier assumptions that urethane formation reactions proceed via mechanisms where alcohol molecules act as auto‐catalysts. Our results show that it is essential to consider several transition states corresponding to different reaction orders to enable agreement with experimental observations. Urethane cleavage seems to be catalyzed by an isourethane, leading to an observed 2nd‐order dependence of the reaction rate on the urethane concentration. The results of our study support a deeper understanding of the reactions as well as a better description of reaction kinetics and will therefore help in catalyst development and process optimization.