A simple computational model for predicting pi-facial selectivity in reductions of sterically unbiased ketones: on the relative importance of electrostatic and orbital interactions

A simple computational model explains and predicts pi-facial selectivity in nucleophilic additions to sterically-free carbonyls. The model, based on MNDO, uses two sets of calculations. One measures electrostatic and polarization effects using a test charge to represent the nucleophile, while the other models the hydride ion to determine the added role of orbital interactions. Using these two, the approach is able to reproduce most empirically-established selectivities, especially with the hydride model.