Ab Initio and DFT Study of the Reaction Mechanism of Diformylketene with Formamide

Ab initio and DFT calculations have been carried out to study the reaction mechanism between diformylketene and formamide. Gas-phase calculations show that the mechanism is concerted in contrast to the results of a previous paper. However, although it appears there is one single transition state, the characteristics of its structure reveal a very asynchronous reaction mechanism. The reaction is clearly exothermic and as well has a rather small activation energy. Its pseudopericyclic character has been confirmed by calculation of magnetic properties. The effect of solvent has been analyzed by using the Onsager and PCM methods:  substantial changes have not been found in solution.