Quantum mechanical investigation of the effect of catalyst fluorination in the intermolecular asymmetric Stetter reaction

The asymmetric intermolecular Stetter reaction was investigated using the B3LYP and M06-2X functionals. Fluorination of a triazolium bicyclic catalyst had been found to significantly influence reaction yields and enantiomeric ratios. Computations indicate that the improved reactivity of the fluorinated catalyst is due to better electrostatic interactions between the nitroalkene and catalyst. Computational investigations of preferred conformations of the ground state catalyst and acyl anion equivalent, and the transition structures leading to both enantiomers of the products, are reported.