Theoretical investigation of the cycloaddition reaction betweenisocyanides and benzylidenepentanedion e

The stepwise reaction mechanism of the [1+4] cycloaddition reaction between alkyl isocyanides (contains methyl benzene isocyanide, tert-butyl isocyanide, cyclohexyl isocyanide) with 3-Benzylidene- 2,4-pentanedione both in the gas phase and in solvent was studied theoretically with B3LYP method using 6-311++G(d,p) basis set. The potential energy of all structures participated in the reaction path has been evaluated. Unexpectedly, the second step of all reactions was recognized as the ratedetermining step. The best product configuration was recognized based upon the quantum mechanical calculations. The effect of substituted alkyl groups on the potential energy surfaces was investigated.Also, the natural bond orbital method (NBO) applied for better understanding of molecular interaction.

Keywords:

Theoretical study , Alkyl isocyanides , [1+4] cycloaddition , Reaction mechanism