Theoretical investigation on isomerization of Et2AlCN to Et2AlNC and cyanation of aldimine

The chemical fixation of diethylaluminum cyanide (Et2AlCN) reacting with N-benzylideneaniline to produce 2-phenyl-2-(phenylamino)acetonitrile has been investigated by using DFT/B3LYP methods. The solvent effect is assessed using the continuum solvent model based on the SCRF/PCM method at the PCM/B3LYP/6-31G∗ level. Our results reveal that based on isomerization of Et2AlCN to Et2AlNC and their ambidextrous CN groups which will result in C-attack or N-attack to imine center carbon, there are four possible reaction paths to be found. The analysis of activation barriers shows the carbon atom in Et2AlNC firstly attacking the imine C atom in N-benzylideneaniline to afford the five-membered-ring transition state 4′a is favorable in the gas phase and in solvent toluene. The changing geometries and Wiberg bond indices with NBO analysis indicate the reaction process and the overall reaction is exothermic.