Investigation of the reaction mechanism between dimethyl acetylenedicarboxylates and isocyanide: a DFT study

In this study, the reaction mechanisms of isocyanide-based three-component reaction have been firstly investigated using density functional theory (DFT). Two possible reaction channels (including channels a and b have been suggested and investigated in detail. For both channels a and b, the reaction is initiated by the nucleophilic attack of 2,6-dimethylphenyl isocyanide (R1) on diamethyl acetylenedicarboxylate (R2). Our calculated results indicate that reaction channel b is the most energetically favorable channel. The computational results reveal that channel b contains three reaction steps. Firstly, it is the nucleophilic attack on R2 by R1. The second step is the formation of C17-C37 bond. The last step is a bimolecula proton transfer process.