Theoretical Prediction of the 31P NMR Chemical Shift of the Hexa-Coordinate Phosphorus Intermediate for the Phosphoryl Ester Exchange and N→O Migration Reactions of Dimethyloxyphosphoryl-Threonine
Ab initio GIAO magnetic shielding calculations have been carried out on the hexa-coordinate phosphorus intermediate and the corresponding reactant and product for the N→O migration reaction of dimethyloxyphosphoryl-threonine. The calculated results lead us to predict that the 31P NMR chemical shift of the hexa-coordinate phosphorus intermediate is −138 ppm, while the 31P chemical shifts of the corresponding reactant and product are 4.9 ppm and −6.6 ppm, respectively.