Stereoselective O-phosphorylation of aldehydes and ketones via phospha-Brook rearrangement: the stereochemistry and intermolecular mechanism

Abstract

A base-catalyzed O-phosphorylation of aldehyde/ketone with R_P-menthyl phenylphosphinate afforded phosphonates. The mechanism was proposed as an intermolecular S_N@P reaction of α-hydroxy phosphinate. In an intermediate, the C–P bond was transferred from the equatorial to axial position via Berry pseudorotation, and then was cleaved with the leaving of a carbon anion. The P-retention and C-racemization could be satisfactorily explained by the mechanism.